A. Introduction. This Handbook introduces the basics of the metric system, including conversion factors from the Inch-Pound System to the System International (SI) Metric System.

1. The Bureau is committed to doing engineering design in the metric system, thereby meeting the requirements of the Metric Conversion Act and Executive Order 12770

2. Bids to date have not shown detectable premiums for metric. No additional funds are being allocated for metric construction.

B. Metric Products. Some "hard" metric products have minimum order quantities that may limit them to a project involving renovation of an entire floor or more of a building. Most products, however, are identical to the English-dimensioned products and can be used on any project.

Most modular products are undergoing "hard conversion" -- their dimensions will change to new rounded metric numbers. Suspended ceiling grids will convert to 600 x 600 mm or 600 x 1200 mm. Drywall, plywood, and rigid insulation will change to 1200 mm widths, but their thicknesses will remain the same to eliminate the need for recalculating fire and acoustic rates and U-values. Raised access flooring will go to 600 x 600 mm. Brick will become 90 x 57 x 190 mm and block will become 190 x 190 x 390 mm; both will use 10-mm mortar joints and be laid in 600-mm modules. Before specifying hard metric products be sure they are available from the suppliers in the area where the project is located.

What happens to the traditional 2-by-4 wood stud? Two-by-four inches is a nominal size, not a finished size. Neither wood studs nor other framing lumber will change in cross-section, but they will be spaced at 400 mm instead of 16 inches -- about 1/4 inch closer together. Batt insulation installed between studs might not change in width; instead, there will be more of a "friction fit."

There are other products in the same category. A 2-inch pipe has neither an inside nor an outside diameter of 2 inches. A 24-inch I-beam contains no actual 24-inch dimension. These products won't change sizes either; they'll just be relabeled. Perhaps they will eventually get new nominal names, such as 50-mm pipe or 600-mm beams. However, with or without names, the metrication process won't be affected.

C. Metric Facts.

1. Length. The meter has been defined as the wavelength of a specified radiation equal to 3.2808398 ft. For conversion, one foot equals 0.3048 meters or 304.8 millimeters.

For shorter lengths, the meter is divided into 1000 parts or millimeters (mm); 25.4 mm = 1 inch.

2. Tertiary Powers of 10. Use tertiary powers of 10 (.001, 1, 1000 for units of measure, i.e., millimeters, meters, and kilometers. In most cases, intermediate powers (.01, .1, 100) should not be used in construction, i.e., centimeters, decimeters, and hectometers.

2. Power. In the inch-pound system, power is expressed in many different ways -- Btu per hour, horsepower, foot/pound force per second, etc. This multitude of terms results in the need for much converting. In the metric system, power consumption, as well as the power output of an electric motor, is expressed in watts, making the efficiency of the motor easily calculated.

For conversion purposes, there are 746 watts in one horsepower.

Problem: A gasoline engine is rated at 100 hp. What is its power output expressed in metric units?

Solution: 100 hp. x (746/hp)W x k/1000 = 74.6 kW

3. Pressure and Stress. In the inch-pound system, pressure and stress are expressed in many ways, including pounds per square inch (psi), inches of mercury, and inches of water. In the metric system, the unit for pressure and stress is the pascal. One pascal is defined as the force of one newton exerted over an area of one square meter. In symbolic language, this is shown as Pa = N/m2.

One psi equals 6894 pascals. Since the pascal is such a small unit, pressure and stress are often given in kilopascals (kPa) or megapascals (MPa),

Problem: The operating pressure in a boiler is 125 psi. Express this in pascals with a convenient prefix.

Solution: 125 lb/in2 x 6894 Pa/lb/in2 x k/1000 = 892 kPa

D. Applying the Metric System.

1. Becoming Familiar with the Size of Metric Units. When you hear the terms inch, foot, yard, mile, ounce, pound, pint, quart, and gallon, you have good idea of their size. That's because we use these terms almost every day.

Although we often hear metric terms such as millimeter, centimeter, meter, kilometer, gram, kilogram, and liter, we feel much less comfortable with them because we don't have a good picture of their size. In this section our goal is to provide visual reminders and ball park sizes for these metric units.

A few basic comparisons are worth remembering to help visualize or at least roughly convert between U.S. and metric:

a. One inch is just a fraction (1/64 inch) longer than 25 mm (1 inch = 25.4 mm; 25 mm = 63/64 inch).

b. Four inches are about 1/16 inch longer than 100 mm (4 inches = 101.6 mm; 100 mm = 3-15/16 inches).

c. One foot is about 3/16 inch longer than 300 mm

(12 inches = 304.8 mm; 300 mm = 11-13/16 inches).

d. Four feet are about 3/4 inch longer than 1200 mm

(4 feet = 1219.2 mm; 1200 mm = 3 feet, 11-1/4 inches).

e. Therefore, the metric equivalent of a 4 by 8 sheet of plywood or drywall would be 1200 x 2400 mm.

f. Rounding down from multiples of 4 inches to multiples of 100 mm makes dimensions exactly 1.6 percent smaller and areas about 3.2 percent smaller.

g. One meter equals about 39-1/2 inches, just under 3-1/2 inches longer than a yard.

2. Units of Length. The stem unit of length is the meter. A meter is a little longer than a yard, about a yard plus the length of a piece of chalk.

Illustration 1 - Meter (a little longer than a yard).

A millimeter, which is one-thousandth of a meter, is about the thickness of a dime.

Illustration 2 - Millimeter (about the thickness of a dime).

A kilometer, which is 1000 meters, is about 5/8ths of a mile. If a mile is about 10 city blocks, then a kilometer is about 6 blocks. A mile is 4 times around a typical nonmetric track. A kilometer is about 2.5 times around the track.

Illustration 3 - Kilometer (about 5/8 of a mile).

3. Units of Weight. The stem unit of weight is the gram. A gram is quite small. A package of Sweet 'n LowTM has a weight of one gram. A paper clip also has a weight of about one gram.

Illustration 4 - Gram (contents of a package of artificial sweetener).

A milligram, which is one-thousandth of a gram, is much smaller. Imagine dividing up the contents of a package of artificial sweetener into 1000 equal parts. One of those parts is a milligram.

A kilogram, which is 1000 grams, is a little over 2 pounds (2.2 pounds) - about the weight of a good-sized orange.

4. Units of Volume. The base unit for volume is the liter. A liter is somewhat larger than a quart. A quart is 32 fluid ounces, while a liter is 33.8 fluid ounces, or about a quart and a quarter of a cup.

Illustration 5 - Liter (about a quart and a quarter of a cup).

A milliliter, which is one-thousandth of a liter, is quite small. It takes about 5 milliliters to make one teaspoon.

E. Basic Metric.

1. Base Units. In the metric system, all quantities are derived using decimal units derived from the following base units of measurement, six of which are used in design and construction.

TABLE 1 BASIC UNITS

Quantity/Measurement S.I. Unit Symbol
length
mass
time
electric current
temperature
luminous intensity
meter
kilogram
second
ampere
kelvin
candela
m
kg
s
A
K
cd

Celsius temperature (oC) is more commonly used than kelvin (K), but both have the same temperature gradients. Celsius temperature is simply 273.15 degrees warmer than kelvin, which begins at absolute zero.

2. Decimal Prefixes. Although prefixes mega (M) for one million (106), giga (G), for one billion (109), micro () for one millionth (10-6), and nano (n) for one billionth (10-9) are used in some engineering calculations, the two most commonly used specialized prefixes are below:

TABLE 2 DECIMAL PREFIXES

Prefix Symbol Order of Magnitude Expression
kilo
milli
k
m
103
10-3
1000 (one thousand)
0.001 (one thousandth)

3. Plane and Solid Angles. The radian (rad) and steradian (sr) denote plane and solid angles. They are used in lighting work and in various engineering calculations. In surveying, the units degree (), minute ('), and second (") continue in use.

4. Derived Units. Other derived units used in engineering calculations are shown below:

TABLE 3 DERIVED UNITS

Quantity Name Symbol Expression
frequency
force
pressure, stress
energy, work, quantity of heat
power, radiant flux
electric charge, quantity
electric potential
capacitance
electric resistance
electric conductance
magnetic flux
magnetic flux density
inductance
luminous flux
illuminance
hertz
newton
pascal
joule
watt
coulomb
volt
farad
ohm
siemens
weber
tesla
henry
lumen
lux
Hz
N
Pa
J
W
C
V
F

S
Wb
T
H
lm
lx
Hz=1/s
N=kgm/s2
Pa=N/m2
J=Nm
W=J/s
C=As
V=W/A or J/C
F=C/V
=V/A
S=A/V or 1/
Wb=Vs
T=Wb/m2
H=Wb/A
lm=cdsr
lx=lm/m2

5. Liter, Hectare, and Metric Ton. The liter (L) measures liquid volume. The hectare (ha) measures surface area. The metric ton (t) is used to denote mass.

F. Metric Rules.

1. Rules For Writing Metric Symbols and Names.

a. Print unit symbols in lower case except for liter (L) or unless the unit name is derived from a proper name.

b. Print unit names in lower case, even those derived from a proper name.

c. Leave a space between a numeral and a symbol (write

45 kg or 37 oC, not 45kg or 37oC or 37o C).

d. Do not leave a space between a unit symbol and its decimal prefix (write kg, not k g).

e. Do not use the plural of unit symbols (write 45 kg, not 45 kgs), but do use the plural of written unit names (several kilograms).

f. Do not mix names and symbols (write Nm or newton meter, not Nmeter or newtonm).

g. Do not use a period after a symbol (write "12 g", not "12 g.") except when it occurs at the end of a sentence.

2. Rules For Writing Numbers.

a. Use a zero before the decimal marker for values less than one (write 0.45 g, not .45 g).

b. Use spaces instead of commas to separate blocks of three digits for any number over four digits (write 45 138 kg or 0.004 46 kg or 4371 kg).

3. Rules for Conversion and Rounding.

a. To convert numbers from inch-pound to metric, round the metric value to the same number of digits as there were in the inch-pound (11 miles at 1.609 km/mi equals 17.699 km, which rounds to 18 km).

b. To avoid mistakes, convert mixed inch-pound units (feet and inches, pounds and ounces) to the smaller inch-pound unit before converting to metric and rounding (10 feet, 3 inches = 123 inches; 123 inches x 25.4 mm = 3124.2 mm; round to 3120 mm).

c. In a "soft conversion", an inch-pound measurement is mathematically converted to its exact (or nearly exact) metric equivalent. With hard conversion, a new rounded, rationalized metric number is created that is convenient to work with and remember. A hard conversion is also an item or component that is made to metric size by a manufacturer.

4. Rules For Linear Measurement (Length).

a. Use only the meter and millimeter in building design and construction.

b. Use the kilometer for long distances and the micrometer for precision measurements.

c. Do not use the centimeter.

d. For survey measurement, use the meter and the kilometer.

5. Rules For Area.

a. The square meter is most commonly used.

b. Large areas may be expressed in square kilometers and small areas in square millimeters.

c. The hectare (10 000 square meters) is used for land and water measurement only.

d. Do not use the square centimeter.

e. Linear dimensions such as 40 x 90 mm may be used; if so, indicate width first and length second.

6. Rules For Volume and Fluid Capacity.

a. The cubic meter is most commonly used for volumes in construction and for storage tanks.

b. Use the liter (L) and millimeter (mL) for fluid capacity (liquid volume). One liter is 1/1000 of a cubic meter or 1000 cubic centimeters.

G. Conversion Factors for Length, Area, and Volume. See

Table 4 for guidance when converting from Inch-Pound Units to Metric Units. Appendix 2 contains complete tables of conversion factors.

TABLE 4

LENGTH, AREA, and VOLUME CONVERSION FACTORS

QUANTITY FROM INCH-POUND UNITS TO METRIC UNITS MULTIPLY BY:
Length mile
yard
foot
foot
inch
km
m
m
mm
mm
1.609 344
0.914 4
0.304 8
304.8
25.4

Area square mile
acre
acre
square yard
square foot
square inch
km2
m2
ha (10 000 m2)
m2
m2
mm2
2.590 99
4046.856
0.404 685 6
0.836 127 36
0.092 903 04
645.16

Volume acre foot
cubic yard
cubic foot
cubic foot
cubic foot
100 bd feet
gallon
cubic inch
m3
m3
m3
cm3
L (1000 cm3)
m3
L (1000 cm3)
mm3
1233.49
0.764 555
0.028 316 8
28 316.85
28.316 85
0.235 974
3.785 41
16 387.064

NOTE: Underline denotes exact number.

H. Estimating Basics.

1. Construction Time/Costs. Metric design and construction take the same number of months as English projects. No adjustments have been made to time expectations.

2. Cost. These estimates shall be done in metric units only.

3. Design Costs. There will be no change to the standard design fee charts used to calculate design costs, given that: a. specifications are metric,

b. metric estimating tools are offered,

c. criteria are metric,

d. most codes and standards are in metric, and

e. sample drawings exist for most items.

4. Estimating Tools. The R.S. Means Company, Inc. offers metric estimating handbooks. There are several construction metric databases available from private firms.

I. Preferred Metric Dimensions in Building Construction.

1. In design and construction, most measurement statements involve linear measurement. Frequently, such measurement statements are not independent; they are part of a set or sequence of values. A common set of preferred dimensions is used to establish the geometry of a building as well as the sizes of constituent components or assemblies. To select the most appropriate metric values during conversion of linear dimensions, it is helpful to appreciate the concept of dimensional coordination, which involves special dimensional preferences for buildings and building products. Because all preferred dimensions are related to a building module, the term modular coordination is sometimes substituted. In building construction, the fundamental unit of size is the basic module of 100 mm. It is slightly shorter than the 4" (101.6 mm) module that has been used in the United States, and should not be equated with this customary module because metric modular product dimensions will be 1.6% shorter.

2. The basic module of 100 mm has already been endorsed as the basic unit of size in metric dimensional coordination in the United States. Preferred dimensions of buildings and preferred sizes of building components should be whole multiples of 100 mm, wherever practicable.

3. Building products vary from small components placed by hand that range in size up to about 1000 mm, to larger elements placed by mechanical means that may range up to 12 000 mm.

Building dimensions vary from small thicknesses of structural elements and dimensions of small spaces to very large spaces with dimensions of 60 000 mm or more in special structures. To ensure efficient use of materials, preferred dimensions play an important part in design, production, and construction.

4. It is important to appreciate that preferred dimensions in the context of metric dimensional coordination are reference dimensions or ideal dimensions rather than actual dimensions. Allowances for joints, tolerances, and deviations are taken into account in the determination of actual dimensions. For example, when a component is described by a preferred size of 400 mm, this dimension includes an allowance for half a joint width on either side of the component, and the actual dimension is less to ensure fit in a coordinating space. If the design joint thickness is 10 mm, the dimension for use as a manufacturing target dimension will be 390 mm.

5. The construction process involves joining many individual and often repetitive components, assemblies, or elements into an organized whole. Therefore, building dimensions that are highly divisible multiples of the basic module are superior to prime number multiples.

J. Construction Trades. The metric units used in the construction trades are charted below. The term "length" includes all linear measurements (that is, length, width, height, thickness, diameter, and circumference).

TABLE 5
CONSTRUCTION UNITS and TERMINOLOGY
TRADE QUANTITY UNIT SYMBOL
Carpentry length meter, millimeter m, mm
Concrete length meter, millimeter m, mm
area square meter m2
volume cubic meter m3
temperature degree Celsius oC
water capacity liter (1000 cm3) L
mass (weight) gram, kilogram g, kg
cross-sec. area square millimeter mm2
Drainage length meter, millimeter m, mm
area square meter m2
volume cubic meter m3
slope millimeter/meter mm/m
Electrical length meter, millimeter m, mm
frequency hertz Hz
power watt, kilowatt W, kW
elec. current ampere A
elec. potential volt, kilovolt V, kV
resistance ohm
energy kilojoule, megajoule kJ, MJ
Excavating length meter, millimeter m, mm
volume cubic meter m3
Glazing length meter, millimeter m, mm
area square meter m2
HVAC length meter, millimeter m, mm
force newton, kilonewton N, kN
volume cubic meter m3
temperature degree Celsius oC
capacity liter (1000 cm3) L
velocity meter/second m/s
rate of heat flow watt, kilowatt W, kW
energy, work kilojoule, megajoule kJ, MJ
Masonry length meter, millimeter m, mm
area square meter m2
mortar volume cubic meter m3
Painting length meter, millimeter m, mm
area square meter m2
capacity liter, milliliter(cm3) L, mL
Paving length meter, millimeter m, mm
area square meter m2
Plastering length meter, millimeter m, mm
area square meter m2
water capacity liter (1000 cm3) L
Plumbing length meter, millimeter m, mm
mass gram, kilogram g, kg
capacity liter (1000 cm3) L
pressure kilopascal kPa
Roofing length meter, millimeter m, mm
area square meter m2
slope millimeter/meter mm/m
Steel length meter, millimeter m, mm
mass gram, kilogram
metric ton (1000 kg)
m2
t

Surveying length meter, kilometer m, km
area square meter
square kilometer
hectare (10,000 m2)
m2
km2
ha

plane angle degree (non-metric)
minute (non-metric)
second (non-metric)
o
'
"

Trucking distance kilometer km
volume cubic meter m3
mass metric ton (1000 kg) t

K. Drawing and Specifications Guidance.

1. Drawing Scales.

a. Metric drawing scales are expressed in nondimensional ratios.

b. Nine scales are preferred; 1:1 (full size), 1:5, 1:10, 1:20, 1:50, 1:100, 1:200, 1:500, and 1:1000. Three others have limited usage: 1:2, 1:25, and 1:250.

TABLE 6
COMPARISON BETWEEN INCH-FOOT and METRIC SCALES

Inch-Foot Scales

Ratios
Metric Scales
Remarks

Preferred Other
Full Size 1:1 1:1 No Change
Half Size 1:2 1:2 No Change
4" = 1'-0"
3" = 1'-0"
1:3
1:4

1:5

Close to 3" scale

2" = 1'-0"
1-1/2" = 1'-0"

1" = 1'-0"
1:6
1:8

1:12

1:10

Between 1" and 1-1/2" scales

3/4" = 1'-0"

1/2" = 1'-0"
1:16

1:24

1:20

1:25

Between 1/2" and 3/4" scales
Close to 1/2" scale

3/8" = 1'-0"
1/4" = 1'-0"

1" = 5'-0"
3/16" = 1'-0"
1:32
1:48

1:60
1:64

1:50

Close to 1/4" scale

1/8" = 1'-0"

1" = 10'-0"
3/32" = 1'-0"
1:96

1:120
1:128

1:100

Close to 1/8" scale

1/16" = 1'-0" 1:192
1:200

Close to 1/16" scale

1" = 20'-0" 1:240
1:250

Close to 1" = 20'-0" scale

1" = 30'-0"
1/32" = 1'-0"
1" = 40'-0"
1:360
1:384
1:480

1:500

Close to 1" = 40'-0"

1" = 50'-0"
1" = 60'-0"
1" = 1 chain
1" = 80'-0"
1:600
1:720
1:792
1:960

1:1000

Close to 1" = 80'-0"

2. Metric Units Used on Drawings.

a. Use only one unit of measure on a drawing. Except for large-scale site or cartographic drawings, the unit should be the millimeter (mm). Centimeters shall not be used. On large scale site or cartographic drawings, the unit should be the meter.

b. Metric drawings use millimeters (mm) exclusively. Each drawing should have the following note on it:

"All DIMENSIONS ARE MILLIMETERS (mm) UNLESS OTHERWISE NOTED."

c. Metric drawings should almost never show decimal millimeters (for example: 2034.5), unless a high precision part or product thickness is being detailed. Use whole millimeters (for example: 2035).

d. Dual dimensions should not be used; for example, 200 mm (7-7/8").

e. A space should separate groups of three digits on drawing dimensions. This allows faster and more accurate dimensional interpretation. For example: A 20-meter dimension would show as 20 000 (twenty thousand millimeters).

3. Drawing Sizes.

a. The ISO "A" series drawing sizes are preferred metric sizes for design drawings. A0 is the base drawing size with an area of one square meter. Smaller sizes are obtained by halving the long dimension of the previous size. All A0 sizes have a height-to-width ratio of one to the square root of 2 (1:1.414).

b. There are five "A" series sizes:

(1) A0 1189 x 841 mm (46.8 x 33.1 inches)

(2) A1 841 x 594 mm (33.1 x 23.4 inches)

(3) A2 594 x 420 mm (23.4 x 16.5 inches)

(4) A3 420 x 297 mm (16.5 x 11.7 inches)

(5) A4 297 x 210 mm (11.7 x 8.3 inches)

4. Codes and Standards. Codes and standards needed for design are available today in metric. Codes and standards have not hindered renovation or new construction designs in metric to date. For codes or standards not in metric, rounding techniques have proven sufficient.

5. Submittals. To assist manufacturers with metric conversion, the following submittal classes should be utilized. These classes should be supplemented for each project.

a. Class 1. Drawings That Must Be Metric Only. English units are not permitted on these submittals. Drawings must use metric scales. In general, any drawing that is job specific, and is custom generated for this project, must be in metric only. Here are some samples:

Floor Plans

Reflected Ceiling Drawings

Stairwell Erection Drawings

Foundation Wall Drawings

Concrete/Rebar Installation Drawings

Sitework Drawings

Sheeting and Shoring Plans

Steel Erection/Fabrication Drawings and Details

Precast Manhole Drawings

Door Schedules

Wall Paneling Drawings

Caisson Details

Millwork Drawings

Cabinet Work Details

Toilet Room Details

Ductwork Drawings

Pipe Installation Drawings

HVAC Schedules

Switchgear Drawings

Electrical Component Layout Drawings

Signage Drawings

b. Class 2. Data That Must Be Metric Only. The following types of items must be submitted in metric only. Data generated specifically for these projects must also be submitted in SI only.

Concrete Design Mixes

Concrete Test Data

Core Bore Depths Data

Aggregate Mixes (must show metric sieves)

Mechanical Air and Water Flow or Balancing Data

Environmental or Hazardous Material Data

Most Test Data

Other data generated for the project that is not in bound, preprinted catalogs or publications.

6. Specifications.

a. Millimeters (mm). Metric specifications should use mm for most measurements, even large ones. Use of mm is consistent with dimensions in major codes, such as the National Building Code (Building Officials and Code Administrators International, Inc.) and the National Electric Code (National Fire Protection Association).

Use of mm leads to integers for all building dimensions and nearly all building product dimensions, so use of the decimal point is almost completely eliminated.

b. Meters (m). Meters may be used where large, round metric sizes are involved.

Example: "Contractor will be provided an area of 5 by 20 meters for storage of materials."

c. Centimeters (cm). Centimeters should never be used in specifications. Centimeters are not used in major codes. Use of centimeters leads to extensive usage of decimal points. Whole millimeters should be used for specific measurements, unless extreme precision is being indicated. A credit card is about 1 mm thick.

(1) Example 1 - Mortar Joint Thickness. If a 3/8-inch mortar joint between brick is needed, this would convert to 9.525 mm. Whole mm should be used, so specify 10 mm joint thickness.

(2) Example 2 - Stainless Steel Thickness. Bath accessories are commonly made from 22-gauge (0.034-in) thick stainless steel. Exact conversion is 0.8636 mm. This is a precision measurement; an appropriate conversion is 0.86 mm.

(3) Example 3 - Concrete Thickness. Concrete shall be 200 mm thick.

(4) Example 4 - Clearance. Clearance shall be 1500 mm.

In specifications, the unit symbols (e.g., m or mm) are almost always present. Little room exists for confusion. On drawings, using mm eliminates the need to write m or mm and eliminates decimal usage for all but large-scale civil and road design drawings.

A small class of items reference standards using centimeters or square centimeters, such as fire ratings for some products. These items only, which account for less than 2 percent of specification references, should make reference to centimeters or square centimeters.

d. Nominal Technique. Many specification references can effectively use nominal mass, nominal volume, or nominal length technique. For example, if one gallon (3.785 L) of product X is required, the specification could be rewritten using nominal volume, requiring 4 L ( 0.25 L). Users can then say "4 liters" when referencing this item, while still allowing the current product to be submitted.

e. Professional Rounding. This technique takes the result of simple mathematical rounding and applies professional judgment. First, a small discussion of metric design is necessary. The basic module of metric design is 100 mm. The multimodules and submodules, in preferred order, are 6000, 3000, 1200, 600, 300, 100, 50, 25, 20, and 10.

(1) How to Use Professional Rounding.

(a) Convert the dimension mathematically. Let's say a pavement width in some codes becomes 914 mm minimum.

(b) Select a replacement dimension.

(i) 1000 would be the preferred re-placement.

(ii) 950 would be used only with justification.

(iii) 900 would offend the code and could not be used.

(2) How to Correctly Apply Professional Judgment to Design Criteria.

(a) Example: Conversion of an Existing Code Requirement

(i) Determine the non-offending direction. National Building Code Article 1011.3 requires 44 inches (1118 mm) of unobstructed pedestrian corridor width. However, 1118 mm is not a clean number. It should be rounded to facilitate the cleanest construction possible. Narrower offends the code. The non-offending direction is larger, so it is better to round up.

(ii) Every effort should be made to keep design dimensions in increments of 100 mm, which is the basic module, or in multimodules.

f. Measurements. All measurements in construction specifications should be stated in metric. Until existing specification systems are fully converted, the specifier may:

(1) Specify metric products. Check to see if the products to be specified are available in metric sizes.

(2) Refer to metric or dual unit codes and standards. The American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc. (ASHRAE), American Society of Mechanical Engineers (ASME), and American Concrete Institute (ACI), among others, publish metric editions of some standards. The Building Officials and Code Administrators (BOCA), as well as the American Society for Testing and Materials (ASTM) and the National Fire Protection Association (NFPA), publish their documents with dual units (both metric and inch-pound measurements). In addition, most handicapped accessibility standards and a number of product standards are published with dual units. The metric measurements are virtually exact, soft numerical conversions that, over time, will be changed through the consensus process into rounded hard metric dimensions. For now, use the soft metric equivalents.

(3) Convert existing unit measurements to metric. Follow the conversion rules below.

g. Standards, Criteria, and Product Information. For organizations that publish construction standards, criteria, or product information: Review all active documents and follow the conversion rules below. The standards referenced in e. and f. below may be consulted for additional guidance conversion.

(1) Whenever possible, convert measurements to rounded, hard metric numbers. For instance, if anchor bolts are to be imbedded to a depth of 10 inches, the exact converted length of 254 mm might be rounded to either 250 mm (9.84 inches) or 260 mm (10.24 inches). The less critical the number, the more rounded it can be, but ensure that allowable tolerances or safety factors are not exceeded. When in doubt, stick with the exact soft conversion.

(2) Round to "preferred" metric numbers.

(a) The preferred numbers for the "1 foot = 12 inches" system are, in order of preference, those divisible by 12, 6, 4, 3, and 2.

(b) Preferred metric numbers are, in order, those divisible by 10, 5, and 2, or decimal multiples thereof. National Bureau of Standards (NBS) Technical Note 990, The Selection of Preferred Metric Values for Design and Construction, explains the concept of preferred numbers in detail and states in its foreword:

It is widely recognized that a transfer to a metric technical environment based upon a soft conversion -- that is, no change other than the description of the physical quantities and measurements in metric units -- would cause considerable longer term problems and disadvantages due to the encumbrance of the resulting awkward numbers. The overall costs of soft conversion could greatly outweigh any savings due to its short term expediency.

The Technical Note provides a rational basis for the evaluation and selection of preferred numerical values associated with metric quantities. Precedent has shown that the change to metric units can be accompanied by a change to preferred values at little or no extra cost, especially in specifications, codes, standards, and other technical data.NBS Technical Note 990; The Selection of Preferred Metric Values for Design and Construction

(3) Use hand calculators or software conversion programs that convert inch-pounds to metric. They are readily available and are indispensable to the conversion process. Simply check with any store or catalog source that sells calculators or software.

(4) Be careful with the decimal marker when converting areas and volumes; metric numbers can be significantly larger than inch-pound numbers (a cubic meter, for instance, is one billion cubic millimeters).

(5) Use ASTM E621, Standard Practice For the Use of Metric (SI) Units in Building Design and Construction, as a basic reference.

(6) Follow the rules for usage, conversion, and rounding in ASTM E 380, Standard Practice of Use of the International System of Units (SI), Sections 3 and 4; or American National Standards Institute (ANSI) 268, Metric Practice, Sections 3.5 and 4.

Chapter 2

A. Architectural.

1. Block.

a. Standard sizes are 90, 140, and 190 mm thick, with a 190 x 390 mm face. Normal metric modular block is 190 x 190 x 390 mm. This nearly equates to 7-1/2 x 7-1/2 x 15-3/8 inches. American modular block is 194 x 194 x 397 mm, quite similar to metric block. Stacking nonmortar joint block is usually 203 x 203 x 406 mm. Hard metric block has 12.5 blocks per m2.

b. Metric block has been installed on U.S. projects. Some metric blocks are being supplied using molds borrowed from sources that already owned them, eliminating mold purchase costs.

c. The standard mortar joint for block is 10 mm.

2. Brick.

a. The "metric modular brick" is the most common. Its size is 90 x 57 x 190 mm (3-9/16 x 2-1/4 x 7-1/2 inches). Jumbo brick is 90 x 90 x 190 mm.

b. American modular brick is:

(1) 3-5/8 x 2-1/4 x 7 5/8 inches (92 x 57 x 194 mm) when a 3/8-inch joint is used.

(2) 3-1/2 x 2-3/16 x 7-1/2 inches (89 x 56 x 190 mm) when a 1/2 inch joint is used.

c. Thus the standard American modular brick used with a 1/2-inch joint is so close to the metric modular brick that it can be used with only a slight variation in joint thickness during field installation.

d. Three vertical courses of metric modular brick with 10 mm joints equals 201 mm, which is rounded to 200. Two jumbo courses equals 200. Weepholes are mostly spaced in 100 mm sizes. (e.g., 600 mm). Seventy-five modular metric bricks per m2, 50 metric jumbo bricks per m2.

e. Metric brick has been used on U.S. projects. Standard mortar joint for brick and block is 10 mm. Brick should be specified in metric, regardless of whether ASTM C 216 or ASTM C 62/AASHTO M 114 is used.

3. Carpet.

a. Most firms have the dies and can or do make metric carpet tile. Most common sizes are 500 x 500 mm and 600 x 600 mm.

b. Minimum orders are available (several hundred square meters or less). As the industry goes metric, premiums for minimums will shrink or be eliminated.

4. Ceiling Systems.

a. Many domestic manufacturers regularly make hard metric tiles and grids for use in metric projects. Most common sizes are 600 x 600 mm and 600 x 1200 mm.

b. Many design and construction projects, both renovation and new construction, are using the 600 x 600 mm system.

c. Many facilities with 2 x 2 grids are not adversely affected by use of new 600 x 600 mm grids.

d. With hard metric ceilings, room dimensions can be multiples of 600 mm, giving clean, rounded dimensions to construction personnel for layout.

5. Drywall.

a. Only sheet length and width are classified in hard metric. The standard sheet width is 1200 mm. Lengths available are 2400 mm and several longer sizes.

b. Thicknesses remain the same to minimize code impact. Most architects show these as 13 x 16 mm on drawings, instead of the exact 12.7 and 15.9 mm. Standard stud spacing is 400 mm, as it is the closest to 16 inches and is an even multiple of the sheet size.

6. Doors.

a. A common metric door size is 900 x 2100 mm, although 1000 x 2000 mm is sometimes used. This may be used on metric projects where other project specific design criteria are satisfied.

b. Louvers and glass should be in hard metric dimensions, such as 300 x 300 mm, 450 x 450 mm, etc.

c. Door thicknesses will remain the same, being identified by the nominal mm equivalent. Most architects soft-convert door thickness and are using nominal 45 mm as standard.

d. Most door frame section dimensions are being rounded to the nearest 1 mm (e.g., 13, 25, 41, 50, or 80 mm). Lengths and widths match hard metric door sizes and should be hard metric. (e.g., 900 x 2100 mm)

7. Elevators.

a. Capacities should be specified to the next lowest 50 kg. (e.g., 40,000 lb = 18 144 kg). Signage in the elevator would show 18 100 kg only.

b. Most manufacturers can make hard metric platforms. Specifying 50 mm platform sizes is preferred, but allow standard English platform sizes to be submitted. (For example, 5'7" x 7' platform = 1702 x 2134 mm. Specify as 1700 x 2100 mm, but approve the standard English size) Note: Code and criteria requirements may restrict this approach and must be considered on each project.

c. Speeds should be in meters/second, shown to two digits (e.g., 0.64 m/s, 0.51 m/s).

d. Thus, manufacturers supply standard product, and rounded numbers appear in specifications and drawings as well as to the public.

8. Glass.

a. ASTM C 1036 gives metric sizes for flat glass, heat absorbing glass, and wired glass.

b. Glass shall be specified in mm only.

c. Thicknesses for Type 1, Transparent Flat Glass are 1, 1.5, 2, 2.5, 2.7, 3, 4, 5, 5.5, 6, 8, 10, 12, 16, 19, 22, 25, and 32.

9. Lumber.

a. Two by four-inch is a nominal size. Neither wood studs nor other framing lumber will change in cross-section. A 2 x 4-inch piece can be soft converted to 51 x 102 mm (nominal) or 38 x 89 mm actual. The actual dimensions in millimeters would most commonly be used.

b. Millimeter dimensions are frequently used in exact layout work only, such as layout of cabinetry, but 2 x 6 and

2 x 10 boards will still be used.

10. Plywood.

a. Projects using plywood should specify metric sheets.

b. Thickness is the same to minimize production impacts. The standards are 12.7 and 19.05 mm, commonly given nominal thicknesses on drawings (e.g., 19 mm).

11. Roofing.

a. Use millimeters squared for areas.

b. State membrane thickness in millimeters only.

c. Lap widths should be even millimeters. (e.g., 100 mm, 150 mm, etc.)

12. Sheet Metal.

a. Most specification references use gauge numbers followed by the decimal inch thickness.

Example: 22 gauge (0.034 inch).

b. Metric specifications use millimeter thickness. It is not the intent to change the thickness of currently used sheeting. The thickness under "Specify" is thinner than the actual gauge thickness, since specifications give minimum thickness.

The following chart may be used to specify sheet metal:

Gauge Inch Exact mm Specify (< exact) mm % Thinner
32 0.0134 0.3404 0.34 0.1
30 0.0157 0.3988 0.39 2.2
28 0.0187 0.4750 0.47 1.1
26 0.0217 0.5512 0.55 0.2
24 0.0276 0.7010 0.70 0.1
22 0.0336 0.8534 0.85 0.4
20 0.0396 1.0058 1.00 0.6
18 0.0516 1.3106 1.30 0.8
16 0.0635 1.6129 1.60 0.8
14 0.0785 1.9939 1.90 4.7
12 0.1084 2.7534 2.70 1.9
10 0.1382 3.5103 3.50 0.3
8 0.1681 4.2697 4.20 1.6

This schedule was developed since no existing material was found to clearly identify existing sheeting in metric units. Until a more efficient method is developed to address this issue, specifiers may wish to retain the gauge number in specifications, coupling this with a rounded mm size.

c. For example: Provide grab bar with a minimum wall thickness of 18 gauge (0.051 inch) should be replaced with: Provide grab bar with minimum wall thickness of 1.3 mm. Since 18 gauge is thicker than 1.3 mm, 18 gauge is acceptable.

d. Show minimum thickness in millimeters only. Specifying 1 or 0.1 mm thicknesses wherever possible. (e.g., 1 mm, 1.6 mm). Hard metric sheet metal is obtainable, even in smaller quantities.

13. Stone. Stone, such as granite and marble, should be specified in hard metric (e.g., 30 or 50 mm thick, or 100 x 300).

14. Metal Studs. Common metal studs are available in the following nominal mm sizes, which closely align with the dimensions in the standard English sizes: 42, 64, 92, 102, and 153 mm. A 22 mm hat channel for furring is also common. both wood and metal studs are soft converted and will not change in actual cross section.

15. Woodwork. Custom casework, such as cabinets, built-in benches, shelves, security desks, and judges benches, should be developed in hard metric to the fullest degree possible.

a. Cabinets. Many cabinet widths are shown as increments of 50 mm. (e.g., 450, 500 mm wide).

b. Lockers. Dimensions should be furnished in metric sizes.

B. Civil Engineering.

1. Units. The metric units used in civil and structural engineering are:

a. meter (m)

b. kilogram (kg)

c. second (s)

d. newton (N)

e. pascal (Pa)

2. Rules for Civil Engineering.

a. There are separate units for mass and force.

b. The kilogram (kg) is the base unit for mass, which is the unit quantity of matter independent of gravity.

c. The newton (N) is the derived unit for force (mass times acceleration, or kgm/s2). It replaces the unit "kilogram-force" (kgf), which should not be used.

d. The newton meter designates torque, not the joule.

e. The pascal (Pa) measures pressure and stress (Pa=N/m2).

f. Structural calculations should be shown in MPa or kPa (megapascals or kilopascals).

g. Plane angles in surveying (cartography) will continue to be measured in degrees (either decimal degrees or degrees, minutes, and seconds) rather than the metric radian.

h. Percentages should be used primarily for long, standing slopes, while ratios should generally be used for shorter or steeper distances. Since both are basically "dimensionless"--that is, they refer to each other instead of a specific standard of measurement--either could be used as required. Just remember to follow current, standard designating practices regarding each.

When using percentages, follow this rule: Percent x 10 = mm/m (vertical distance in millimeters per horizontal meter) For example: 2% x 10 = 20 mm/m, and 45% = 450 mm/m.

i. Road construction must be designed using metric units. For additional guidance, use the AASHTO Guide to Metric Conversion for geometric design values, lane and shoulder widths, curb heights, sight distances, curvatures, and other values.

TABLE 8

CIVIL AND STRUCT ENGINEERING CONVERSION FACTORS

Quantity
From Inch-Pound Units To Metric Units
Multiply by
Mass lb
kip
kg
metric ton
0.453 592
0.453 592

Mass/unit length plf kg/m 1.488 16
Mass/unit area pcf kg/m2 1.482 43
Mass density pcf kg/m3 16.018 5
Force lb
kip
N
kN
4.448 22
4.448 22

Force/unit length plf
klf
N/m
kN/m
14.593 9
14.593 9

Pressure, stress, modulus of elasticity psf
ksf
psi
ksi
Pa
kPa
kPa
MPa
47.880 3
47.880 3
6.894 76
6.894 76

Bending moment, torque, moment of force ft-lb
ft-kip
Nm
kNm
1.355 82
1.355 82

Moment of mass lbft kgm 0.138 255
Moment of inertia lbft2 kgm2 0.042 140 1
Second moment of area in4 mm4 416 231
Section modulus in3 mm3 16 387.064

NOTE: Underline denotes exact number.

kip = 1000 lb

metric ton = 1000 kg

C. Structural Engineering.

1. Units. The metric units used in structural engineering are:

a. meter (m)

b. kilogram (kg)

c. second (s)

d. newton (N)

e. pascal (Pa)

2. Rules for Structural Engineering.

a. There are separate units for mass and force.

b. The kilogram (kg) is the base unit for mass, which is the unit quantity of matter independent of gravity.

c. The newton (N) is the derived unit for force (mass times acceleration, or kgm/s2). It replaces the unit "kilogram-force" (kgf), which should not be used.

d. The newton meter designates torque, not the joule.

e. The pascal (Pa) measures pressure and stress (Pa=N/m2).

f. Structural calculations should be shown in MPa or kPa (megapascals or kilopascals).

g. Design dimensions must be rounded. Bar spacing, wall and slab thickness, and similar dimensions must be even mm

(e.g., 100, 250, or 400 mm), not exact conversions (e.g., 305 mm).

h. Structural steel shall be specified in metric only, such as 250 MPa. Shapes shall be specified according to the millimeter sizes and dimensions in ASTM A 6M.

i. Wind pressures are given in Pa, while wind speeds are most frequently given in m/s.

3. Structural Strategies.

a. Fasteners. Use ASTM A 325M and A 490M metric bolts. There are seven standard metric bolt sizes, which replace the nine bolts currently used. Standard sizes are 16, 20, 22, 24, 27, 30, and 36 mm.

b. Steel.

(1) ASTM A 6/A 6M lists both inch and mm dimensions of the shapes.

(2) Another reference is the International Standards Organization (ISO) standard for steel.

c. Floorload.

(1) Calculations are in kPa, but floorloading can be in kilograms (kg) per square meter because many dead and live loads are given in kg. Use the following rounded, slightly conservative, rule: kPa x 100 = kg/m2 (e.g., 5 kPa x 100 = 500 kg/m2)

(2) The chart below gives kPa strength ratings that can be used to replace the psf strength rating.

Previous (psf) New (kPa) Percent Stronger
50 2.5 4.4
80 4 1.8
100 5 4.4
120 6 4.4
150 7.5 4.4
200 10 4.4
250 12 0.2
300 15 4.4
350 17 1.4
400 20 4.4
450 22 2.1
500 24 0.2

(3) A typical office rating is 5 kPa, with 4 kPa and

1 kPa components. Drawings and calculations should reflect these numbers only.

(4) In existing facilities, the preferred method is to convert values to exact kPa and then round to the next lowest 0.1 kPa.

D. Surveying and Project Layout.

1. Databases of hundreds of thousands of horizontal and vertical survey control points on which U.S. surveys are based have been completely metric since 1983. USGS, which produces topographic maps of terrain elevations, has digitally mapped the U.S. surface. The ground distance between each pair of digitized points is 30 meters. Thus, survey and mapping data needed to do metric design and construction in the United States is available.

2. The following information can be used as guidance on how site plans and topographic maps are to be executed:

a. Contour intervals utilize either 1000, 500, or 250 mm as contour intervals, depending on site slope.

b. Elevation measurements are given in mm.

c. Benchmark elevations are converted from feet to mm.

3. Examples:

a. Benchmark is 314.15 feet. Convert to 95 753

b. Sample Finished Floor Elevation: 105 025

c. Sample Top of Curb: TC 305 224

d. Sample Bottom of Curb: BC 305 024

e. Sample Contour Lines:

------------------106 000--------------------

------------------105 500--------------------

4. Large mapping scales use metric symbols. 1:2000 is written as 1:2k, 1:5,000,000,, as 1:5M. Contour lines may also be given in meters.

5. Electronic surveying and mapping equipment provides data in metric squared units. Many states utilize electronic data measurement (EDM) equipment, which almost always can work in metric units.

6. Plane angles in surveying (cartography) will continue to be measured in degrees (either decimal degrees or degrees, minutes, and seconds) rather than the metric radian.

7. Percentages should be used primarily for long, standing slopes, while ratios should generally be used for shorter or steeper distances. Since both are basically dimensionless-- that is, they refer to each other instead of a specific standard of measurement--either could be used as required. Just remember to follow current, standard designating practices regarding each. When using percentages, follow this rule: Percent x 10 = mm/m (vertical distance in millimeters per horizontal meter) For example: 2% x 10 = 20 m/m, and 45% = 450 mm/m.

E. Materials Guidance (General).

1. Concrete.

a. Concrete strength is specified throughout the country in MPa. The following strengths should be used in metric construction. The general purpose concrete strengths are reduced from 6 strengths to 4 strengths. Strengths above 35 MPa should be specified in 5 MPa intervals (40, 45, 50, 55, etc.).

Previous psi Exact Conversion MPa Specify MPa
2 500
3 000
3 500
4 000
4 500
5 000
17.23
20.67
24.12
27.56
31.01
34.45
20
20 or 25*
25
30
35
35

*If code requires 3000 psi, then 25 MPa should be used; otherwise, it is a professional judgment on whether to use 20 or 25. Refer to the PSI versus MPa chart in the Graphic Standards Book.

b. ACI 318M, metric version, should now be used.

c. Slump Limits on metric projects always use 10 or 5 mm increments (e.g., 75, 80, or 90 mm).

2. Concrete Pipe.

a. ACPA 5.0 states that concrete pipe can now be specified using hard metric ASTM and AASHTO standards.

b. Reinforced concrete pipe (RCP) is specified as ASTM

C 76M/AASHTO M 170M.

c. ASTM C76 RCP meets the hard metric standard, since tolerances were set in the hard metric standard to accept current product.

d. For nonreinforced concrete pipe, sizes are as follows:

C 76M
sizes
(mm)
300 375 450 525 675 750 825 900 1050
1200 1350 1500 1650 1800 1950 2100 2250 2400

C 14M
sizes
100 150 200 250 300 375 450 525 600
675 750 825 900

3. Geotechnical. Geotechnical reports shall be metric units only and, equally important, shall be in rounded metric units. Bearing and side friction values shall be in MPa, rounded to 1 or 0.1 MPa increments wherever possible.

4. Reinforcement.

a. Metric projects will use ASTM A 615M reinforcing bars for general purpose applications. The A 615M reinforcing bar comes in Grades 300 and 400, indicating 300 and 400 MPa yield strength.

b.There are 8 bar sizes, which replace the 11 bar sizes currently used, as listed below:

Size
Diam (mm) Area (mm2)
Size
Diam (mm) Area (mm2)
3
4
5
9.52
12.70
15.87
71
129
200
10M
15M
20M
11.3
16.0
19.5
100
200
300

6
7
8
19.05
22.22
25.40
284
387
510
25M
30M
35M
25.2
29.9
35.7
500
700
1000

9
10
11
28.65
32.25
35.81
645
819
1006
45M
55M
43.7
56.4
1500
2500

14
18
43.00
57.32
1452
2581

c. Some applications may need A 616M, A 617M, A 706M, or

A 775M. Note that a nominal 15 mm bar is called a "Number 15 bar."

5. Pipe. Steel pipe and copper tube sizes will not now change, since American sizes are still used in many parts of the world. Designate tube sizes by nominal mm size. Hard metric pipe sizing may be used in the future. ASTM B 88M provides standard hard metric copper tube sizes. During the transition to metric units, the following paragraph and chart should be placed on the mechanical cover sheet:

"ALL SIZES ARE INDUSTRY-STANDARD ASTM A 53 PIPE AND ASME B 88 TUBE DESIGNATED BY THEIR NOMINAL MILLIMETER (mm) DIAMETER EQUIVALENT. SEE CHART BELOW."

Nominal Size
Inch mm
1/2 15
3/4 20
1 25
1-1/4 32
1-1/2 40
2 50
2-1/2 65
3 80
3-1/2 90
4 100
5 125
6 150

6. General Fasteners.

a. U.S. industry is now using metric fasteners extensively.

b. The Thomas Register lists hundreds of firms under Metric Fasteners, Metric Screws, and Metric Bolts. The Industrial Fasteners Institute (IFI) has guides for fastener types and producers.

c. Many pieces of mechanical and electrical equipment already use both metric and English fasteners. Metric fasteners use M numbers. (For example, M10 x 40 is a nominal 10 mm diameter and 40 mm length.)

d. Metric socket head cap screws, set screws, hex bolts, and similar items are available.

7. Anchor Bolts. Metric anchor bolts (e.g., L, J and U bolts) are available. ASTM F 568 gives metric chemical and mechanical data for carbon steel anchor bolts and studs, and also references ANSI dimensional standards.

a. ISO Metric Grades. As given in ISO 898 and ASTM F 568, ISO metric grades should be used. Many anchor bolts are made from low carbon steel grades, such as ISO classes 4.6, 4.8, and 5.8.

b. Preferred Diameters. Preferred nominal diameters for items such as anchor bolts and threaded rod are as shown below. Reference individual standards prior to specification. Sizes are given between M5 and M45, as these are commonly used in construction.

1: M5 6 8 10 12 16 20 24 30 36 42

2: M14 18 22 27 33 39 45

3: M45 7 9 11 15 17 25 26 28 32 35 38 40

8. Fastener Data. Tables 9 and 10 provide much of the data available for different metric fasteners.

TABLE 9
FASTENER DATA

Basic Product

Product Type and
Head Style

Size Range

For Dimensions
Refer to:

For Mechanical and/or Performance Properties Refer To:

Metric Bolts hex M5-M100 ANSI/ASME B18.2.3.5M

ASTM F #568

ASTM F#486M

ASTM F #738

heavy hex M12-M36 ANSI/ASME B18.2.3.6M
round head short square neck (carriage) M8-M20 ANSI/ASME B18.5.2.1M
round head square neck (carriage) M5-M24 ANSI/ASME B18.5.2.2M
bent M5 and larger IFI 528
heavy hex structural M12-M36 ANSI/ASME B18.2.3.7M ASTM A#325M
ASTM A#490M

hex transmission tower M16-M24 IFI 541 IFI 541

Metric Screws hex cap M5-M100 ANSI/ASME B18.2.3.1M
ASTM F#568

ASTM F#468M

ASTM F#738

formed hex M5-M24 ANSI/ASME B18.2.3.2M
heavy hex M12-M36 ANSI/ASME B18.2.3.3M
hex flange M5-M16 ANSI/ASME B18.2.3.4M
heavy hex flange M10-M20 ANSI/ASME B18.2.3.9M
hex lag 5-24mm ANSI/ASME B18.2.3.8M see note 3

Metric Studs double end M5-M100 IFI 528 ASTM F#568
ASTM F#468M
ASTM F#736

continuous thread M5-M100

Metric Locking Screws prevailing torque, non-metallic insert M1.6-M36 see note 3 IFI 524
chemical coated M6-M20 see note 3 IFI 525

Metric Socket Screws socket head cap M1.6-M48 ANSI/ASME B 18.3.1M ASTM A#574M F#837M
socket head shoulder 6.5-25mm ANSI/ASME B 18.3.3M ASTM F#835M

ASTM A#574M

ASTM F#879M

socket button head cap M3-M16 ANSI/ASME B18.3.4M
socket countersunk head cap M3-M20 ANSI/ASME B18.3.5M
socket set 1.6-24mm ANSI/ASME B18.3.6M ANSI/ASME B.18.3.6M
ASTM F#912M
ASTM F#880M

Metric Nuts hex, style 1 M1.6-M36 ANSI/ASME B18.2.4.1M ASTM A#563M

ASTM F#467M

ASTM F#836M

ASTM A#194M

hex, style 2 M3-M36 ANSI/ASME B18.2.4.2M
slotted hex M5-M36 ANSI/ASME B18.2.4.3M
hex flange M5-M20 ANSI/ASME B18.2.4.4M
hex jam M5-M36 ANSI/ASME B18.2.4.5M
heavy hex M12-M100 ANSI/ASME B18.2.4.6M

Metric Prevailing-Torque Nuts hex, steel M3-M36 ANSI/ASME B18.16.3M ANSI/ASME B18.16.1M

ANSI/ASME B18.16.2M

hex flange, steel M6-M20

a. When only the property class number is shown, the class is standard in both ISO and ASTM documents. Properties specified in each are identical except for minor exceptions. Where differences exist, the F 568 values are given.

b. To compute the proof load, yield strength, or tensile strength in kilonewtons for a bolt, screw, or stud, divide the stress value, MPa as given in Table 10, for the property class by 1000 and multiply this answer by the tensile stress area of the product's screw thread as given in Table 9.

c. In general, identification markings are located on the top of the head and preferably are raised.

d. Class 5.8 products are available in lengths 150 mm and less.

e. Caution is advised when considering the use of Class 12.9 products. The capabilities of the fastener manufacturer, as well as the anticipated service environment, should be carefully considered. Some environments may cause stress corrosion cracking of nonplated as well as electroplated products.

TABLE 10
MECHANICAL REQUIREMENTS FOR CARBON STEEL

EXTERNALLY THREADED FASTENERS -- METRIC SERIES
Property Class
Designation

Nominal Size of Product

Material and
Treatment
Mechanical Requirements Property Class
Ident. Marking

Proof Load Stress,
MPa

Yield Strength,
MPa, Min

Tensile Strength, MPa, Min

Prod. Hardness, Rockwell
Surface Max Core
Min Max
4.6 M5-M100 low or medium carbon steel 225 240 400 -- B67 B95 4.6
4.8 M1.6-M16 low or medium carbon steel, fully or partially annealed 310 340 420 -- B71 B95 4.8
5.8 M5-M24 low or medium carbon steel, cold worked 380 420 520 -- B82 B95 5.8
8.8 M16-M72 medium carbon steel; the product is quenched and
tempered
600 660 830 30N56 C23 C34 8.8
A325M
Type 1
M16-M36 A325M
8S

8.8 M16-M36 low carbon boron steel; the product is quenched and
tempered
600 660 830 30N56 C23 C34 8.8
A325M
Type 2
A325M
8S

A325M
Type 3
M16-M36 atmospheric
corrosion resistant steel; the product is quenched and
tempered
600 660 830 30N56 C23 C34 A325M
8S3

9.8 M1.6-M16 medium carbon steel; the product is quenched and tempered 650 720 900 30N58 C27 C36 9.8
9.8 M1.6-M16 low carbon boron steel; the product is quenched and
tempered
650 720 900 30N58 C27 C36 9.8
10.9 M5-M20 medium carbon boron steel; the
product is quenched and tempered
830 940 1040 30N59 C33 C39 10.9
10.9 M5-M100 medium carbon alloy steel; the product is quenched and
tempered
830

940 1040 30N59 C33 C39 10.9
A490M
Type 1
M12-M36 A490M
10S

10.9 M5-M36 low carbon boron steel; the product is quenched and tempered 830 940 1040 30N59 C33 C39 10.9
A490M
Type 2
M12-M36 A490M
10S

A490M
Type 3
M12-M36 atmospheric corrosion resistant steel; the product is quenched and
tempered
830 940 1040 30N59 C33 C39 A490M
10S3

12.9 M1.6-M1000 alloy steel; the
product is quenched and tempered
970 1100 1220 30N63 C38 C44 12.9

F. Electrical Engineering.

1. Units. The metric units used in electrical engineering and their symbols are shown below:

meter (m)

second (s)

candela (cd)

radian (rad)

steradian(sr)

ampere (A)

coulomb (C)

volt (V)

farad (F)

henry (H)

ohm ()

siemens (S)

watt (W)

hertz (Hz)

weber (Wb)

tesla (T)

lumen (lm)

lux (lx)

TABLE 11

METRIC UNITS USED IN CONSTRUCTION

(ELECTRICAL)

QUANTITY UNIT SYMBOL
length meter, millimeter m, mm
frequency hertz Hz
power watt, kilowatt W, kW
energy megajoule, kilowatt hour MJ, kWh
electric current ampere A
electric potential volt, kilovolt V, kV
resistance ohm

2. Rules for Electrical Engineering.

a. The only unit change for electrical engineering is the renaming of conductance from "mho" to siemens (S).

b. The lux (lx) is the unit for illuminance and replaces lumen per square foot and footcandle.

c. Luminance is expressed in candela per square meter (cd/m2) and replaces candela per square foot, footlambert, and lambert.

3. Conversion Factors. Table 12 identifies the conversion factors unique to electrical engineering.

TABLE 12

ELECTRICAL ENGINEERING CONVERSION FACTORS

QUANTITY FROM INCH-POUND UNITS TO METRIC UNITS MULTIPLY BY
Power, radiant flux W W 1 (same unit)
Radiant intensity W/sr W/sr 1 (same unit)
Radiance W/(srm2) W/(srm2) 1 (same unit)
Irradiance W/m2 W/m2 1 (same unit)
Frequency Hz Hz 1 (same value)
Electric current A A 1 (same unit)
Electric charge Ahr C 3600
Electric potential V V 1 (same unit)
Capacitance F F 1 (same unit)
Inductance H H 1 (same unit)
Resistance 1 (same unit)
Conductance mho S 100
Magnetic flux maxwell Wb 10-8
Mag. flux density gamma T 10-9
Luminous intensity cd cd 1 (same unit)
Luminance lambert
cd/ft2
footlambert
kcd/m2
cd/m2
cd/m2
3.183 01
10.763 9
3.426 26

Luminous flux lm lm 1 (same unit)
Illuminance foot-candle lx 10.763 9

NOTE: Underline denotes exact number.

4. Conduit. Conduit will not change size in metric. It will be classified by a nominal mm size. The following paragraph and chart may be placed on the electrical drawing sheet.

"ALL CONDUIT SIZES ARE INDUSTRY-STANDARD ENGLISH-SIZE CONDUIT DESIGNATED BY THEIR ROUNDED NOMINAL MILLIMETER (mm) DIAMETER EQUIVALENT. SEE CHART BELOW."

Nominal Size
Inch mm
1/2 15
3/4 20
1 25
1-1/4 32
1-1/2 40
2 50
2-1/2 65
3 80
3-1/2 90
4 100
5 125
6 150

5. Cabling. Metric sizes are available.

a. Projects with medium and larger wire requirements may wish to start using international sizes, where permitted by governing codes and criteria.

b. ASTM B 682 gives metric sizes. Common sizes (in mm2) are, 0.5, 0.75, 1, 1.5, 2.5, 4, 6, 10, 16, 25, 35, 50, 70, 95, 120, 150, 185, 240, and 300.

c. Many projects have begun to refer to existing sizes by millimeter squared dimensions to become familiar with the millimeter squared scale. On the chart below are millimeter squared equivalents with detailed rounding. In some cases, rounding to the nearest 0.1, 1, or more square millimeters may be feasible. Use professional judgment.

AWG mm2 kcm mm2
22 0.506 250 126.68
20 0.517 300 152.01
18 0.82 350 177.35
16 1.31 400 202.68
14 2.08 450 228.0
12 3.31 500 253.4
10 5.26 550 278.7
9 6.6 600 304.0
8 8.37 650 329.4
7 10.6 700 354.7
6 13.30 750 380.0
5 16.8 800 405.4
4 21.15 900 456.0
3 26.66 1000 506.7
2 33.63 1100 557.4
1 42.41 1200 608.1
1/0 53.48 1250 633.4
2/0 67.44 1300 658.7
3/0 85.03 1400 709.4
4/0 107.2 1500 760.1
1600 810.7
1700 861.4

1800 912.1
1900 962.7
2000 1013.4

6. Fiber Optics. Most cables are made to metric dimensions, so these will be specified in hard metric (e.g., 125 m fiber cable). Illumination levels are in lux (lx).

7. Lighting Fixtures. Use hard metric fixture sizes for lay-in type. Common sizes are 600 x 600 mm and 600 x 1 200 mm. Use the 600 x 600 mm size with sockets on one end wherever possible as it is easier to manufacture in hard metric. Use either a compact tube or a T-8 U-tube for higher efficiency.

G. Mechanical Engineering.

1. Units. The metric units used in mechanical engineering are listed below.

meter (m)

kilogram (kg)

second (s)

joule (J)

watt (W)

kelvin (K) or degree

Celsius (C)

pascal (Pa)

radian (rad)

newton (N)

TABLE 13

METRIC UNITS USED IN CONSTRUCTION

Quantity Unit Symbol
length meter, millimeter m, mm
volume cubic meter m3
capacity liter (1000 cm3) L
velocity meter/second m/s
volume flow cubic meter/second
liter/second
m3/s
L/s

temperature degree Celsius C
force newton, kilonewton N, kN
pressure kilopascal kPa
energy, work kilojoule, megajoule kJ, MJ
rate of heat flow watt, kilowatt W, kW

2. Rules For Mechanical Engineering.

a. The joule (J) is the unit for energy, work, and quantity of heat. It is equal to a newton meter (Nm) and a watt second (Ws), and it replaces inch-pound units, such as ftlbf.

b. The watt (W) is both the inch-pound and metric unit for power and heat flow. It replaces horsepower, foot pound-force per hour, Btu per hour, calorie per minute, and ton of refrigeration.

c. Moisture movement is expressed by the terms "vapor permeance" and "vapor permeability."

d. The inch-pound unit "perm" continues to represent the degree of retardation of moisture movement. The lower the value, the greater the retardation.

e. The newton (N) is the derived unit for force (mass times acceleration, or (kgm/s2). It replaces the unit "kilogram-force" (kgf), which should not be used.

3. General Guidelines.

a. Temperature. Use Celsius for temperature measurements in new or modernization building projects. Renovation projects where the entire HVAC system is not to be renovated may retain Fahrenheit.

b. Air Distribution. Use a hard metric ceiling grid accompanied by hard metric lay-in diffusers and registers or smaller ones that are cut in.

c. Ductwork. Rectangular metal ductwork is a custom-made product. Hard metric sizes are easier to measure (e.g., 300 x 600 mm). Prefabricated flexible round duct is specified in soft converted sizes.

4. Conversion. Table 14 below provides the conversion factors needed to adjust current plans to metric standards.

TABLE 14

MECHANICAL ENGINEERING CONVERSION FACTORS

Quantity From
Inch-Pound Units
To
Metric Units

Multiply By

Mass/area (density) lb/ft2 kg/m2 4.882 428
Temperature F oC 5/9 (F-32)
Energy, work, quantity of heat kWh
Btu
ftlbf
MJ
J
J
3.6
1 055.056
1.355 82

Power ton (refrig.)
Btu/s
hp (electric)
Btu/h
kW
kW
W
W
3.517
1.055 056
745.700
0.293 071

Heat flux Btu/(f2h) W/m2 3.152 481
Rate of heat flow Btu/s
Btu/h
kW
W
1.055 056
0.293 071 1

Thermal conductivity (k value) Btu/(fthF) W/(mK) 1.730 73
Thermal conductance (U value) Btu/(ft2hF) W/(m2K) 5.678 263
Thermal resistance (R value) (ft2hF)/Btu (m2K)/W 0.176 110
Heat capacity, entropy Btu/F kJ/K 1.899 1
Specific heat capacity, specific entropy Btu/(lbF) kJ/(kgK) 4.186 8
Specific energy, latent heat Btu/lb kJ/kg 2.326
Vapor permeance perm (23 C) ng/(Pasm2) 57.452 5
Vapor permeability perm/in ng/(Pasm) 1.459 29
Volume rate of flow ft3/s
cfm
cfm
m3/s
m3/s
L/s
0.025 316 8
0.000 471 947 4
0.471 947 4

Velocity, speed ft/s m/s 0.304 8
Acceleration ft/s2 m/s2 0.304 8
Momentum lbft/sec kgm/s 0.138 255 0
Angular momentum lbft2/s kgm2/s 0.042 140 11
Plane angle degree rad
mrad
0.017 453 3
17.453 3

NOTE: Underline denotes exact number.

5. Heating, Ventilating, & Air Conditioning (HVAC). Air flow out of registers and diffusers should be rounded to even increments of 5 or 10 L/s wherever possible.

a. Ductwork (Round, Rigid). Most designers are showing hard metric diameters (e.g., 250, 300 mm).

b. Ductwork (Round, Flexible). Many designers are showing flexible round duct in hard metric sizes but are accepting soft metric during construction (e.g., 200 or 250 mm).

c. Ductwork (Rectangular). Use 50 and 100 mm sizes (e.g., 500 x 1000, 250 x 350) unless not possible.

6. Pipes.

a. Steel pipe, ASTM A 53, will not physically change. Pipe is classified by nominal mm sizes.

b. ASTM B 88 M hard metric copper tube sizes are available.

c. Schedule designations remain the same (e.g., Schedule 40, and type K, L, and M).

d. 18 mm may be used for 5/8 inch. All other designations remain the same.

e. The paragraph and chart below may be placed on the mechanical drawing sheet.

"ALL SIZES ARE INDUSTRY-STANDARD ASTM A 53 PIPE AND ASTM B 88 TUBE DESIGNATED BY THEIR NOMINAL MILLIMETER (mm) DIAMETER EQUIVALENT. SEE CHART BELOW."

Nominal Size Nominal Size Nominal Size
Inch mm Inch mm Inch mm
1/2 15 2 50 5 125
3/4 20 2-1/2 65 6 150
1 25 3 80 8 200
1-1/4 32 3-1/2 90 10 250
1-1/2 40 4 100 12 300

7. Schedules.

1. Flow rates, pressures, thermal powers, and other metric criteria on schedules should be rounded wherever possible. The one percent analysis provides a useful technique.

a. Example 1: A fan flow rate converts to 8,022 L/s. 1% is +/- 80.22 L/s. This fan could possibly be shown as minimum 8000 L/s (8 m3/s) and is easier to utilize.

b. Example 2: A pump flow converts to 75.7 L/s. One percent of this is 0.757 L/s. Therefore, 75 L/s could possibly be used.

2. It is important to note that, in some cases, codes or design criteria may not allow this liberty. In other cases, however, 2 or 3% analyses may be feasible, using your professional judgement.

8. Temperature.

a. Mechanical schedule temperatures, design temperatures, leaving and entering temperatures, and others shall be stated in even Celsius (e.g., 5, 12, 25, and 40 degrees C) unless this is not feasible.

b. Construction projects shall use Celsius only. Renovation projects where new control systems are being installed should also use Celsius.

c. HVAC calculations shall be in metric.

d. Thermal ratings for boilers and chillers should be specified in even nominal MW or kW increments (e.g., 2100 kW, 2 MW).

APPENDIX 1

GLOSSARY OF TERMS

Glossary of Terms

-B-

basic module: The fundamental unit of size in the systems of coordination in metric building construction: 100 mm (similar to inches in the inch-pound system).

base units: In the metric system, the meter (length), kilogram (mass), second (time), kelvin (thermodynamic temperature), ampere (electric current), and candela (luminous intensity). The mole is also a base unit, but it a physics term and has no application in BLM work.

-D-

digit: One of the ten Arabic numerals (0-9).

degree Celsius: Related directly to thermodynamic temperature (kelvins). Unit of temperature. Zero degrees Celsius is equivalent to 32 degrees Fahrenheit (the freezing point of water) and 100 degrees Celsius is equivalent to 212 degrees Fahrenheit (the boiling point of water). A Celsius degree is 1.8 times larger than a Fahrenheit degree.

derived units: Units that are formed from base units, supplementary units, and other derived units, e.g., meters per second (m/s).

dimensional coordination: Special dimensional preferences for buildings and building products. In metric dimensional coordination, a common set of preferred dimensions is used to establish the geometry of a building as well as the sizes of constituent components or assemblies. Also called modular coordination.

dual dimensions: The expression of dimensions in both customary and metric units of measure.

-H-

hard conversion: Changing the actual size of a product so that its measurements are in rounded metric sizes.

-I-

inch-pound measurement system: The foot, pound, gallon, degree Fahrenheit system used in the U.S.

inframodular size: A selected dimension smaller than the basic module (100 mm).

intermodular size: A selected dimension larger than the basic module (100 mm) but not a whole multiple of the module.

-K-

kilogram: Base unit of mass (weight). Symbol: kg. The kilogram is equal to 1000 grams and is approximately 2.2 pounds.

-L-

liter: Unit of volume or capacity used mainly to measure quanti ties of liquid or gaseous materials. It is equal to a cubic decimeter. Symbol: L. The liter is 6 percent larger than a quart. A smaller unit is the milliliter (mL), which is 1/1000 of a liter.

-M-

meter: The base unit of length. Symbol: m. The meter is equiv- alent to 39.37 inches. Smaller units are the centimeter (cm), which is 1/100 of a meter (a little less than 1/2 inch), and the millimeter (mm) which is 1/1000 of a meter (a little more than 1/32 inch.) The kilometer (km) is a larger unit and is equal to 0.62 mile.

metrication: The process of converting to the metric system.

-N-

nominal value: A value assigned for the purpose of convenient designation; existing in name only.

-P-

preferred multimodular dimension: A selected multiple of the basic module of 100 mm.

-R-

rounded metric sizes: Sizes expressible in simple numbers based on non-decimal multiples of 1000, 100, 50, 20, 10, 5, 2, and 1 in order. Examples are 500 g, 1 kg, 2 kg, 500 ml, 1 L, 5 L, etc.

-S-

SI: Abbreviation for the modern metric system, the International System of Units (from the French, Systeme International

d'Unites). It evolved from the original French metric system and is currently being used virtually worldwide.

significant digit: Any digit that is necessary to define a value or quantity.

soft conversion: The translation of customary unit measurements to their equivalent values in metric units.

supplementary units: The second class of metric units in the metric system. Units added to the system to enhance its capabilities. There are two units: radian (angles in one plane) and steradian (three-dimensional angles).

APPENDIX 2
CONVERSION TABLES

TO CONVERT MULTIPLY BY TO OBTAIN
acres 4.047 x 10-1
4.047 x 103
1.562 x 10-3
4.840 x 103
hectares
sq. meters
sq. miles
sq. yards

atmospheres 7.348 x 10-3
1.058
1.033 x 104
1.033
7.6 x 102
tons/sq. inch
tons/sq. foot
kgs./sq. meter
kgs./sq. cm
mm of mercury (0 C)

acre-feet 4.356 x 104
1.234 x 103
3.259 x 105
cubic feet
cubic meters
gallons

bars 9.869 x 10-1
1.0 x 106
1.020 x 104
atmospheres
dynes/sq. cm
kgs./sq. meter

btu 1.041 x 101
1.055 x 103
2.928 x 10-4
liter-atmosphere
joules
kilowatt-hours

btu/min 2.356 x 10-2
1.757 x 10-2
horsepower
kilowatts

candle/sq. cm 3.146 lamberts
candle/sq. in 4.870 x 10-1 lamberts
cubic feet 2.832 x 10-2
2.832 x 101
cubic meters
liters

cubic ft/min 4.720 x 10-1 liters/sec
cubic inches 1.639 x 10-5
1.639 x 10-2
cubic meters
liters

cubic meters 6.102 x 104
3.531 x 101
1.308
1.000 x 103
cubic inches
cubic feet
cubic yards
liters

cubic yards 7.646 x 10-1
7.646 x 102
cubic meters
liters

cubic yds/min 1.274 x 101 liters/sec
dynes/sq. cm 9.869 x 10-7
2.953 x 10-5
1.020 x 10-6
atmospheres
in. of mercury (0C)
kilograms

ergs 7.376 x 10-8
1.000 x 107
2.773 x 10-11
foot-pounds
joules
kilowatt-hours

fathoms 1.8288 meters
feet 3.048 x 102
3.048 x 10-1
3.048 x 10-4
millimeters
meters
kilometers

feet/min 1.829 x 10-2
3.048 x 10-1
1.136 x 10-2
kilometers/hour
meters/min
miles/hour

feet/sec 3.048 x 101
1.097
1.829 x 101
centimeters/sec
kilometers/hour
meters/min

foot candle 1.076 x 101 lumen/sq meter (lux)
foot-pounds 1.286 x 10-3
1.356
3.766 x 10-7
btu
joules
kilowatt-hours

foot-lbs/min 3.030 x 10-5
2.260 x 10-5
horsepower
kilowatts

foot-lbs/sec 1.818 x 10-3
1.356 x 10-3
horsepower
kilowatts

gallons 3.785 x 10-3
3.785
cubic meters
liters

gallons/min 2.228 x 10-3
6.308 x 10-2
cubic feet/sec
liters/sec

gausses 1.0 x 10-4 webers/sq meter
grams 9.807 x 10-5
9.807 x 10-3
2.205 x 10-3
joules/cm
joules/meter (newton)
pounds

hectares 2.471
1.076 x 105
acres
square feet

horsepower 4.244 x 101
7.457 x 10-1
btu/min
kilowatts

hp (boiler) 3.352 x 104
9.803
btu/hour
kilowatts

hp-hours 2.547 x 103
2.684 x 106
7.457 x 10-1
btu
joules
kilowatt-hours

inches 2.540 x 101
2.540 x 10-2
millimeters
meters

inches of mercury 3.342 x 10-2
3.453 x 102
atmospheres
kilograms/sq. meter

joules 9.486 x 10-4
1.020 x 10-1
btu
kilogram-meters

kilograms 9.807
2.2046
joules/meter (newton)
pounds

kilograms/sq cm 9.678 x 10-1
2.048 x 103
1.422 x 101
atmospheres
pounds/sq foot
pounds/sq inch

kilograms/sq meter 9.678 x 10-5
2.048 x 10-1
1.422 x 10-3
atmospheres
pounds/sq foot
pounds/sq inch

kilogram-meters 9.296 x 10-3
7.233
9.807
2.723 x 10-6
btu
foot-pounds
joules
kilowatt-hours

kilometers 3.281 x 103
1.094 x 103
6.214 x 10-1
feet
yards
miles (statute)

kilowatts 5.692 x 101
4.426 x 104
1.341
btu/min
foot-lbs/min
horsepower

kilowatt-hours 3.413 x 103
2.655 x 106
3.6 x 106
btu
foot-pounds
joules

lamberts 3.183 x 10-1
2.054
candles/sq cm
candles/sq inch

liters 1.000 x 103
3.531 x 10-2
6.102 x 101
1.308 x 10-3
2.642 x 10-1
2.113
1.057
cubic centimeters
cubic feet
cubic inches
cubic yards
gallons (U.S.)
pints (U.S.)
quarts (U.S.)

liters/min 5.886 x 10-4
4.403 x 10-3
cubic ft/sec
gallons/sec

lumen 7.958 x 10-2 spherical candle pwr
lumen/sq foot 1.076 x 101 lumen/sq meter
lux 9.29 x 10-2 foot-candles
meters 5.468 x 10-1
3.281
3.937 x 101
5.400 x 10-4
6.214 x 10-4
1.094
fathoms
feet
inches
miles (nautical)
miles (statute)
yards

meters/min 1.667
5.468 x 10-2
6.0 x 10-2
3.728 x 10-2
centimeters/sec
feet/sec
kilometers/hour
miles/hour

meters/sec 1.968 x 102
3.6
2.237
feet/minute
kilometers/hour
miles/hour

miles (nautical) 6.076 x 103
1.852
1.1516
2.0254 x 103
feet
kilometers
miles (statute)
yards

miles (statute) 1.6093
8.684 x 10-1
kilometers
miles (nautical)

miles/hour 8.8 x 101
1.467
1.6093
2.682 x 101
feet/minute
feet/second
kilometers/hour
meters/minute

millimeters 3.281 x 10-3
3.937 x 10-2
feet
inches

ounces (avdp) 2.835 x 101
6.25 x 10-2
9.115 x 10-1
grams
pounds
ounces (troy)

ounces (fluid) 1.805
2.957 x 10-2
cubic inches
liters

ounces (troy) 3.1103 x 101
1.097
8.333 x 10-2
grams
ounces (avdp)
pounds (troy)

pints (dry) 3.36 x 101
5.0 x 10-1
5.506 x 10-1
cubic inches
quarts
liters

pints (liquid) 1.671 x 10-2
2.887 x 101
4.732 x 10-4
4.732 x 10-1
cubic feet
cubic inches
cubic meters
liters

pounds (avdp) 4.536 x 102
4.448
4.536 x 10-1
1.458 x 101
1.215
grams
joules/meter (newton)
kilograms
ounces (troy)
pounds (troy)

pounds (troy) 3.7324 x 102
1.3166 x 101
1.2 x 101
8.2286 x 10-1
3.7324 x 10-4
grams
ounces (avdp)
ounces (troy)
pounds (avdp)
tons (metric)

pounds of water 1.602 x 10-2
1.198 x 10-1
cubic feet
gallons

pounds/cubic foot 1.602 x 10-2
1.602 x 101
5.787 x 10-4
grams/cubic cm
kilograms/cu meter
pounds/cubic inch

pounds/cubic inch 2.768 x 101
2.768 x 104
1.728 x 103
grams/cubic cm
kilograms/cu meter
pounds/cubic foot

pounds/sq. foot 4.725 x 10-4
1.414 x 10-2
4.882
6.944 x 10-3
atmospheres
inches of mercury
kilograms/sq meter
pounds/sq inch

pounds/sq. inch 6.804 x 10-2
2.036
7.031 x 102
1.44 x 102
atmospheres
inches of mercury
kilograms/sq meter
pounds/sq inch

quarts (dry) 6.72 x 101 cubic inches
quarts (liquid) 5.775 x 101
9.464 x 10-4
1.238 x 10-3
9.463 x 10-1
cubic inches
cubic meters
cubic yards
liters

rods (survey) 5.029
5.5
1.65 x 101
meters
yards
feet

square feet 2.296 x 10-5
1.44 x 102
9.29 x 10-2
1.111 x 10-1
acres
square inches
square meters
square yards

square inches 6.944 x 10-3
6.452 x 102
7.716 x 10-4
square feet
square millimeters
square yards

square kilometers 2.471 x 102
1.076 x 107
1.0 x 106
3.861 x 10-1
1.196 x 106
acres
square feet
square meters
square miles
square yards

square meters 2.471 x 10-4
1.076 x 101
1.55 x 103
3.861 x 10-7
1.196
acres
square feet
square inches
square miles
square yards

square miles 6.40 x 102
2.788 x 107
2.590
2.590 x 106
3.098 x 106
acres
square feet
square kilometers
square meters
square yards

square millimeters 1.076 x 10-5
1.55 x 10-3
square feet
square inches

square yards 2.066 x 10-4
8.361 x 10-1
3.228 x 10-7
acres
square meters
square miles

temperature C 1.8 (+ 32) temperature F
temperature F (-32) 5.555 x 10-1 temperature C
tons (short) 9.072 x 102
2.0 x 103
2.43 x 103
9.078 x 10-1
kilograms
pounds (avdp)
pounds (troy)
tons (metric)

tons/square foot 9.765 x 103
1.389 x 101
kilograms/sq meter
pounds/sq inch

tons/square inch 1.406 x 106 kilograms/sq meter
watts 3.4129
5.688 x 10-2
1.341 x 10-3
1.0
btu/hour
btu/minute
horsepower
joules/second

watt-hours 3.413
2.656 x 103
btu
foot-pounds

webers/sq inch 1.55 x 103 webers/sq meter
yards 9.144 x 10-1
4.934 x 10-4
5.682 x 10-4
meters
miles (nautical)
miles (statute)

APPENDIX 3
PROJECT PLANS

(Illustrative Examples)

Project Plans - (Illustrative Examples)

A. Architectural

Cabinets 5

Childcare Area 5

Door 6

Garage 8

Guard Rail 9

Landscape 10

Lintel 11

Lobby Renovation 12

Reflected Ceiling 14

Renovation Plan 15

Restroom 16

Security Desk 19

Stair 20

Storefront Detail 23

Wall Section 23

Window 26

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