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Area Conversion Factors
Force Conversion Factors
Hard Conversions for Construction Materials
Length Conversion Factors
Mass Conversion Factors
Pavement Marking Coverage Chart
Pipe Conversion Factors
Plate Conversion Factors
Power Conversion Factors
Pressure or Stress Conversion Factors
Reinforcing Steel Conversion Factors
Sheet Metal Conversion Factors
Sieve Conversion Factors
Symbols
Temperature Conversion Factors
Trades in Construction
Useful Conversion Factors
Volume Conversion Factors
Wire Conversion Factors
The International System of Units (SI) is a modernized version of the metric system established by international agreement. The metric system of measurement was developed during the French Revolution and was first promoted in the U.S. by Thomas Jefferson. Its use was legalized in the U.S. in 1866. In 1902, proposed congressional legislation requiring the U.S. Government to use the metric system exclusively was defeated by a single vote.
SI provides a logical and interconnected framework for all measurements in science, industry, and commerce. The metric system is much simpler to use than the existing English system since all its units of measurement are divisible by 10.
The following list provides the conversion relationship between U.S. customary units and SI (International System ) units. The proper conversion procedure is to multiply the specified value on the left (primarily U.S. customary values) by the conversion factor exactly as given below and then round to the appropriate number of significant digits desired. For example, to convert 11.4 ft to meters: 11.4 X 0.3048 = 3.47472, which rounds to 3.47 meters. Do not round either value before performing the multiplication, as accuracy would be reduced. A complete guide to the SI system and its use can be found in ASTM E 380, Metric Practice.
There is some confusion surrounding the correct value to use when converting the English "foot" measurement to the metric "meter" measurement and vice versa. This confusion stems from the fact that there are two, though slightly different, conversion factors that may be used in this process.
Both values
and
are correct factors that can be used for converting feet to meters.
How is it possible to have two values for the same conversion? To gain an understanding of how this is possible, and why it is allowed to continue, it is necessary to take a brief look at the history of the metric system within the United States.
History
The metric system was developed during the French Revolution in the late 1700's. It was first promoted in the United States by Thomas Jefferson and in 1866 the US Congress officially recognized the metric system as a legal system of units. In 1893, the Office of Weights and Measures (now the National Bureau of Standards), fixed the value of the U.S. "yard" in terms of the meter as follows:
this relation is equivalent to:
Unfortunately, other nations used a slightly different conversion factor. To solve this deviation, a refinement was made in the definition of the yard to bring the US yard and the yard used in other countries into agreement. In 1959 the national standards laboratories of the English-speaking nations agreed to standardize the relation between the yard and the meter as follows:
The new length of yard is shorter by exactly two parts in a million.
At the same time it was decided that any data in feet derived from and published as a result of geodetic surveys within the U.S. would remain with the old standards (1 foot = 12/39.37 meter) pending any further decisions. This foot measurement is called the U.S. Survey foot.
This then, is how we came to have two values for foot-meter conversions. One value, (1 foot = 12/39.37 meter), should be used when converting a measurement that is based on geodetic surveys. The other value, (1 foot = 0.3048 meter), should be used for any other conversions that are not related to geodetic data. Whichever value is used, it should be used consistently throughout that project.
The prefixes and symbols listed below are commonly used to form names and symbols of the decimal multiples and sub multiples of the SI units.
INTERIM UNITS OF MEASURE As suggested by Federal Standard 376B January 27, 1993 |
|
AS USED IN THE STANDARD ITEM TABLE |
METRIC EQUIVALENT |
ACRE | hectare (ha) |
CUBIC FOOT | cubic meter (m3) |
CUBIC YARD | cubic meter (m3) |
GALLON/MGALLON | liter (L), cubic meter (m3) |
HUNDRED | Hundred for traffic buttons |
HUNDRED WEIGHT | kilogram (kg) |
LINEAR FOOT | meter (m) |
MBOARD FEET | cubic meter (m3) |
MILE | kilometer (km) |
NAUTICAL MILE | Nautical Mile |
POUND | kilogram (kg) for mass newton (N) for force |
SQUARE FOOT | square meter (m2) |
SQUARE YARD | square meter (m2) |
TON | tonne (t) |
UNITS OF MEASUREMENT USED IN SPECIAL PROVISIONS AND GENERAL SPECIAL PROVISIONS |
METRIC EQUIVALENT | |
GAGE; GAUGE | METAL THICKNESS | gage (mm) |
FAHRENHEIT | TEMPERATURE | kelvin (K) or degree Celsius (C) |
FATHOM | WATER DEPTH | meter (m) |
FOOT/LBS | TORQUE | newton-meter (N-m) |
LBS/SQ. IN | PRESSURES | kilopascal (kPa) megapascal (MPa) (if very large number) |
LBS/SQ. FT | kilopascal (kPa) | |
LBS/SQ YD | kilopascal (kPa) | |
INCH | LINEAR | millimeter (mm) |
KIPS; KSI | TENSION | kilopascal (kPa) or megapascal (MPa) |
LBS/ACRE | EROSION CONTROL | kilograms/hectare |
LBS/CU. FT. | DENSITY | kilogram per cubic meter (kg/m3) |
MIL | THICKNESS | micrometer (um) |
FT. LBS./SEC. | HORSE POWER | watt (W) |
UNITS OF MEASUREMENTS USED ON CONTRACT PLANS |
METRIC EQUIVALENT |
DEGREES/BEARINGS | No change for surveying. |
STATIONING | 1,000 meters = 1 station |
MILEPOSTS | This one is still under review as mileposts are part of the signing issue. Use mileposts for now, but also state kilometerposts. |
ELEVATIONS | meter (m) |
UNITS OF MEASUREMENTS USED IN COMMERCIAL STANDARDS | METRIC EQUIVALENT |
GALS/HR or MIN (PUMPS) | liters per second (L/s) |
500 GALLON TANKS | cubic meter (m3) but it could also possibly be in liter (L) |
55 GALLON DRUMS | cubic meter (m3) or liter (L) for liquid |
94 LBS/SACK (CEMENT) | kilogram (kg) |
DIAMETER OF REINFORCING STEEL | millimeter (mm) |
LBS/FT OF REINFORCING STEEL | kilogram per meter (kg/m) |
BUSHEL | cubic meter (m3) |
Length | ||
To convert from | to | multiply by |
mile (US Statute) | kilometer (km) | 1.609347 |
inch (in) | millimeter (mm) | 25.4 * |
inch (in) | centimeter (cm) | 2.54 * |
inch (in) | meter (m) | 0.0254 * |
foot (ft) | meter (m) | 0.3048 * |
yard (yd) | meter (m) | 0.9144 * |
Area | ||
To convert from | to | multiply by |
square foot (sq ft) | square meter (sq m) | 0.09290304 E |
square inch (sq in) | square meter (sq m) | 0.00064516 E |
square yard (sq yd) | square meter (sq m) | 0.83612736 E |
acre (ac) | hectare (ha) | 0.4047 |
Volume | ||
To convert from | to | multiply by |
cubic inch (cu in) | cubic meter (cu m) | 0.00001639 |
cubic foot (cu ft) | cubic meter (cu m) | 0.02831685 |
cubic yard (cu yd) | cubic meter (cu m) | 0.7645549 |
U.S. liquid** | ||
gallon (gal) | cubic meter (cu m) | 0.00378541 |
gallon (gal) | liter | 3.785 |
fluid ounce (fl oz) | milliliters (ml) | 29.57353 |
fluid ounce (fl oz) | cubic meter (cu m) | 0.00002957 |
Force | ||
To convert from | to | multiply by |
kip (1000 lb) | kilogram (kg) | 453.6 |
kip (1000 lb) | newton (N) | 4,448.222 |
pound (lb) avoirdupois | kilogram (kg) | 0.4535924 |
pound (lb) | newton (N) | 4.448222 |
Pressure or stress | ||
kip per square inch (ksi) | megapascal (MPa) | 6.894757 |
pound per square foot (psf) | kilogram per square meter (kg/sq m) | 4.8824 |
pound per square foot (psf) | pascal (Pa) | 47.88 |
pound per square inch (psi) | pascal (Pa) | 6,894.757 |
pound per square inch (psi) | megapascal (MPa) | 0.00689476 |
Mass (weight) | ||
pound (lb) avoirdupois | kilogram (kg) | 0.4535924 |
ton, 2000 lb | kilogram (kg) | 907.1848 |
grain | kilogram (kg) | 0.0000648 |
Mass (weight) per length | ||
kip per linear foot (klf) | kilogram per meter (kg/m) | 0.001488 |
pound per linear foot (plf) | kilogram per meter (kg/m) | 1.488 |
Mass per volume (density) | ||
pound per cubic foot (pcf) | kilogram per cubic meter (kg/cu m) | 16.01846 |
pound per cubic yard (lb/cu yd) | kilogram per cubic meter (kg/cu m) | 0.5933 |
Temperature | ||
degree Fahrenheit (F) | degree Celsius (C) | tc=(tF-32)/1.8 |
degree Fahrenheit (F) | kelvin (K) | tk = (tF+459.7)/1.8 |
kelvin (K) | degree Celsius (C) | tc=tk-273.15 |
Energy and heat | ||
British thermal unit(Btu) | joule (J) | 1055.056 |
calorie (cal) | joule (J) | 4.1868E |
Btu/degree | F x hr x ft2 W/m2 - degree K | 5.678263 |
kilowatt-hour (kwh) | joule (J) | 3,600,000E |
British thermal unit per pound (Btu/lb) | calories per gram (cal/g) | 0.55556 |
British thermal unit per hour (Btu/hr) | watt (W) | 0.2930711 |
Power | ||
horsepower (hp) (550 ft-lb/sec) | watt (W) | 745.6999 E |
Velocity | ||
mile per hour (mph) | kilometer per hour(km/hr) | 1.60934 |
mile per hour (mph) | meter per second (m/s) | 0.44704 |
Permeability | ||
darcy | centimeter per second (cm/sec) | 0.000968 |
feet per day (ft/day) | centimeter per second (cm/sec) | 0.000352 |
*indicates that the factor given is exact. **One U.S. gallon equals 0.8327 Canadian gallon. t--A pascal equals 1.000 newton per square meter. |
||
Note: One U.S. gallon of water weighs 8.34 pounds (U.S.) at 60 degrees F. One cubic foot of water weighs 62.4 pounds (U.S.). One milliliter of water has a mass of 1 gram and has a volume of one cubic centimeter. One U.S. bag of cement weighs 94 lbs. |
Quantity | From English Units | To Metric Units | Multiply by* |
Length | |||
mile | km | 1.609347 | |
yard | m | 0.9144** | |
foot | m | 0.3048** | |
inch | mm | 25.40** | |
Area | |||
square mile | km 2 | 2.590 | |
acre | m 2 | 4047 | |
acre | hectare | 0.4047 | |
square yard | m 2 | 0.8361 | |
square foot | m 2 | 0.092 90 | |
square inch | mm 2 | 645.2 | |
Volume | |||
acre foot | m 3 | 1 233 | |
cubic yard | m 3 | 0.7646 | |
cubic foot | m 3 | 0.028 32 | |
cubic foot | L (1000 cm 3) | 28.32 | |
100 board feet | m 3 | 0.2360 | |
gallon | L (1000 cm 3) | 3.785 | |
Mass | |||
lb | kg | 0.4536 | |
kip (1000 lb) | metric ton (1000kg) | 0.4536 | |
Mass/unit length | |||
plf | kg/m | 1.488 | |
Mass/unit area | |||
psf | kg/m 2 | 4.882 | |
Mass density | |||
pcf | kg/m 3 | 16.02 | |
Force | |||
lb | N | 4.448 | |
kip | kN | 4.448 | |
Force/unit length | |||
plf | N/m | 14.59 | |
klf | kN/m | 14.59 | |
Pressure, stress, modules of elasticity | |||
psf | Pa | 47.88 | |
ksf | kPa | 47.88 | |
psi | kPa | 6.895 | |
ksi | MPa | 6.895 | |
Bending moment, torque, moment of force | |||
ft-lb | N . m | 1.356 | |
ft-kip | kN . m | 1.356 | |
* 4 significant digits **denotes exact conversion |
Quantity | From English Units | To Metric Units | Multiply by* |
Moment of mass | |||
lb . ft | kg . m | 0.1383 | |
Moment of inertia | |||
lb . ft2 | kg . m 2 | 0.042 14 | |
Second moment of area | |||
in4 | mm4 | 416 200 | |
Section modulus | |||
in3 | mm3 | 16 390 | |
Power | |||
ton (refrig) | kW | 3.517 | |
Btu/s | kW | 1.054 | |
hp (electric) | W | 745.7 | |
Btu/h | W | 0.2931 | |
Volume rate of flow | |||
ft 3/s | m 3/s | 0.028 32 | |
cfm | m 3/s | 0.000 471 9 | |
cfm | L/s | 0.4719 | |
mgd | m 3/s | 0.0438 | |
Velocity, speed | |||
ft/s | m/s | **0.3048 | |
Acceleration | |||
f/s 2 | m/s 2 | 0.3048 | |
Momentum | |||
lb . ft/sec | kg . m/s | 0.1383 | |
Angular momentum | |||
lb . ft 2/s | kg . m 2/s | 0.042 14 | |
Plane Angle | |||
degree | rad | 0.017 45 | |
mrad | 17.45 | ||
* 4 significant digits **denotes exact conversion |
METRIC CONVERSION – PAVEMENTS | ||||||||
Roadway |
Dimensions
|
Bridge Ht.
|
PCCP Thickness'
|
Resilient
|
Modulus
|
|||
ft
|
m
|
ft
|
m
|
(inches)
|
(mm)
|
psi
|
MPa
|
|
Lane | ||||||||
12
|
3.6
|
14.5
|
4.4
|
9
|
225
|
3,000
|
21
|
|
Shoulder | ||||||||
4
|
1.2
|
16.0
|
4.9
|
10
|
250
|
4,000
|
28
|
|
10
|
3.0
|
11
|
275
|
5,000
|
34
|
|||
12
|
300
|
10,000
|
69
|
|||||
12,000
|
83
|
|||||||
15,000
|
103
|
|||||||
20,000
|
138
|
Typical Density Values |
Axle Loads
|
Tire Loads (per tire width)
|
||||
pcf
|
kg/m 2
|
lbs
|
kN
|
lbs/inch
|
kg/mm
|
|
PCCP |
150
|
2403
|
18,000
|
80
|
500
|
9
|
ACP |
137/0.10' depth
|
2439
|
TYPICAL QUANTITIES | ||||||||||||||
Asphalt Concrete Paving Quantities (metric tons/kilometer) | ||||||||||||||
Depth of Pavement | ||||||||||||||
(ft)
|
0.10
|
0.15
|
0.20
|
0.25
|
0.30
|
0.35
|
0.40
|
0.45
|
0.50
|
0.55
|
0.60
|
0.65
|
0.70
|
0.75
|
(mm)
|
30
|
45
|
60
|
75
|
90
|
105
|
120
|
135
|
150
|
165
|
180
|
195
|
210
|
225
|
Width of Pavement | ||||||||||||||||
(ft)
|
(M)
|
|
|
Metric tons per kilometer
|
|||||||||||||
4
|
1.2
|
|
|
88
|
132
|
176
|
219
|
263
|
307
|
351
|
395
|
439
|
483
|
527
|
571
|
614
|
658
|
6
|
1.8
|
|
|
132
|
198
|
263
|
329
|
395
|
461
|
527
|
593
|
658
|
724
|
790
|
856
|
922
|
988
|
8
|
2.4
|
|
|
176
|
263
|
351
|
439
|
527
|
614
|
702
|
790
|
878
|
966
|
1,053
|
1,141
|
1,229
|
1,317
|
10
|
3.0
|
|
|
219
|
329
|
439
|
549
|
658
|
768
|
878
|
988
|
1,097
|
1,207
|
1,317
|
1,427
|
1,536
|
1,646
|
11
|
3.3
|
|
|
241
|
362
|
483
|
604
|
724
|
845
|
966
|
1,086
|
1,207
|
1,328
|
1,448
|
1,569
|
1,690
|
1,811
|
12
|
3.6
|
|
|
263
|
395
|
527
|
658
|
790
|
922
|
1,053
|
1,185
|
1,317
|
1,448
|
1,580
|
1,712
|
1,843
|
1,975
|
22
|
6.6
|
|
|
483
|
724
|
966
|
1,207
|
1,448
|
1,690
|
1,931
|
2,173
|
2,414
|
2,655
|
2,897
|
3,138
|
3,380
|
3,621
|
24
|
7.2
|
|
|
527
|
790
|
1,053
|
1,317
|
1,580
|
1,843
|
2,107
|
2,370
|
2,634
|
2,897
|
3,160
|
3,424
|
3,687
|
3,950
|
Based on 2439 kg/m 3 ; 30 mm compacted depth = 73.17 kg/m 2 |
Wet Material Thickness
|
Edge Line Coverage
|
Area Coverage
|
|||||
English mils (0.001")
|
Metric mm (0.001M)
|
English Ft/gal
|
Met./Eng. M/gal
|
Metric M/Liter
|
English SF/gal
|
Met./Eng. SM/gal
|
Metric SM/Liter
|
1.0
|
0.025
|
4832
|
1473
|
393.7
|
1611
|
150
|
39.37
|
10.0
|
0.254
|
483
|
147
|
39.4
|
161
|
15
|
3.94
|
15.0
|
0.381
|
322
|
98.2
|
26.2
|
107
|
10
|
2.62
|
19.7
|
0.500
|
245
|
74.8
|
20.0
|
82
|
7.6
|
2.00
|
20.0
|
0.508
|
242
|
73.6
|
19.7
|
81
|
7.5
|
1.97
|
25.0
|
0.635
|
193
|
58.9
|
15.7
|
64
|
6.0
|
1.57
|
30.0
|
0.762
|
161
|
49.1
|
13.1
|
54
|
5.0
|
1.31
|
35.0
|
0.889
|
138
|
42.1
|
11.2
|
46
|
4.3
|
1.12
|
39.4
|
1.000
|
123
|
37.4
|
10.0
|
41
|
3.8
|
1.00
|
40.0
|
1.016
|
121
|
36.8
|
9.8
|
40
|
3.7
|
0.98
|
45.0
|
1.143
|
107
|
32.7
|
8.7
|
36
|
3.3
|
0.87
|
49.2
|
1.250
|
98
|
29.9
|
8.0
|
33
|
3.0
|
0.80
|
50.0
|
1.270
|
97
|
29.5
|
7.9
|
32
|
3.0
|
0.79
|
59.1
|
1.500
|
82
|
24.9
|
6.7
|
27
|
2.5
|
0.67
|
60.0
|
1.524
|
81
|
24.5
|
6.6
|
27
|
2.5
|
0.66
|
78.7
|
2.000
|
61
|
18.7
|
5.0
|
20
|
1.9
|
0.50
|
88.6
|
2.250
|
55
|
16.6
|
4.4
|
18
|
1.7
|
0.44
|
90.0
|
2.286
|
54
|
16.4
|
4.4
|
18
|
1.7
|
0.44
|
98.4
|
2.500
|
49
|
15.0
|
4.0
|
16
|
1.5
|
0.40
|
100.0
|
2.540
|
48
|
14.7
|
3.9
|
16
|
1.5
|
0.39
|
118.1
|
3.000
|
41
|
12.5
|
3.3
|
14
|
1.3
|
0.33
|
120.0
|
3.048
|
40
|
12.3
|
3.3
|
13
|
1.2
|
0.33
|
236.2
|
6.000
|
20
|
6.2
|
1.7
|
7
|
0.6
|
0.17
|
250.0
|
6.350
|
19
|
5.9
|
1.6
|
6
|
0.6
|
0.16
|
255.9
|
6.500
|
19
|
5.8
|
1.5
|
6
|
0.6
|
0.15
|
260.0
|
6.604
|
19
|
5.7
|
1.5
|
6
|
0.6
|
0.15
|
WDB 4.22.97 |
SHEET METAL Most specification references use gage number followed by the decimal inch thickness. Example: 22 gage (0.034 inch) Metric specifications use the absolute mm thickness. It is not the intent of this guidance to change the thickness of currently used sheeting. The following chart may be used to specify sheet metal. The thickness under "Specify" is thinner than the actual gage thickness, since specifications give minimum thickness.
Gage
|
Inch
|
Exact (mm)
|
Specify (mm)
|
Percent Thinner
Than "Exact" Value |
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
|
1.0
|
0.6
|
18
|
0.0516
|
1.3106
|
1.3
|
0.8
|
16
|
0.0635
|
1.6129
|
1.6
|
0.8
|
14
|
0.0785
|
1.9939
|
1.9
|
4.7
|
12
|
0.1084
|
2.7534
|
2.7
|
1.9
|
10
|
0.1382
|
3.5103
|
3.5
|
0.3
|
8
|
0.1681
|
4.2697
|
4.2
|
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 gage number in specifications, and couple this with a rounded mm size in parenthesis.
REINFORCING STEEL
WSDOT Metric projects will continue to use U.S. Customary units on PS&E's.
The following table shows the current U.S. customary rebar sizes in relationship to the respective diameters and cross-sectional areas.
Customary English System
|
Metric Equivalent
|
|||
U. S. Customary Designation |
Diameter (in.)
|
Area (in 2)
|
Diameter (mm)
|
Area (mm 2)
|
#3 |
0.375
|
0.11
|
9.5
|
71
|
#4 |
0.500
|
0.20
|
12.7
|
127
|
#5 |
0.625
|
0.31
|
15.9
|
198
|
#6 |
0.750
|
0.44
|
19.1
|
285
|
#7 |
0.875
|
0.60
|
22.2
|
388
|
#8 |
1.000
|
0.79
|
25.4
|
507
|
#9 |
1.125
|
1.00
|
28.6
|
641
|
#10 |
1.270
|
1.27
|
32.3
|
817
|
#11 |
1.410
|
1.56
|
35.8
|
1007
|
#14 |
1.693
|
2.25
|
43.0
|
1452
|
#18 |
2.257
|
4.00
|
57.3
|
2581
|
SEVEN-WIRE, UNCOATED STRAND FOR PRESTRESSED CONCRETE STRUCTURES The prestressing industry again uses the soft conversion for all dimensional units of prestressing wire. This soft conversion is utilized worldwide and a copy of the equivalent physical properties for Grade 270 low-relaxation strand, as provided by Florida Wire and Cable Company, is provided below:
270 GRADE LOW-RELAXATION ASTM A-416
|
|||||
Nominal Strand Diameter
|
Minimum Strength
|
Area
|
|||
(mm)
|
(in.)
|
(kN)
|
(lb.)
|
(mm 2)
|
(in 2)
|
10
|
(3/8)
|
102.3
|
(23,000)
|
54.8
|
(0.085)
|
11
|
(7/16)
|
137.9
|
(31,000)
|
74.2
|
(0.115)
|
12
|
(15/32)
|
160.1
|
(36,000)
|
85.8
|
(0.133)
|
13
|
(1/2)
|
183.7
|
(41,300)
|
98.7
|
(0.153)
|
14
|
(9/16)
|
230.0
|
(51,700)
|
123.9
|
(0.192)
|
15
|
(0.600)
|
260.6
|
(58,600)
|
140.0
|
(0.217)
|
SIEVES
Sieve Designation (W) | ||||||
Standard
|
Alternative
|
Nominal Sieve Opening
|
Permissible Variation of Average Opening from the Standard Sieve Designation
|
Intermediate Tollerance
|
Maximum Individual Opening
|
Nominal Wire Diameter
|
(in.)
|
(y) + or
|
(x)
|
(x)
|
(mm)
|
||
125 mm
|
5 in.
|
5
|
3.70 mm
|
130.0 mm
|
130.9 mm
|
8.00
|
106 mm
|
4.24 in.
|
4.24
|
3.20 mm
|
110.2 mm
|
111.1 mm
|
6.40
|
100 mm
|
4 in.
|
4
|
3.00 mm
|
104.0 mm
|
104.8 mm
|
6.30
|
90 mm
|
3 1/2 in.
|
3.5
|
2.70 mm
|
93.6 mm
|
94.4 mm
|
6.08
|
75 mm
|
3 in.
|
3
|
2.20 mm
|
78.1 mm
|
78.7 mm
|
5.80
|
63 mm
|
2 1/2 in.
|
2.5
|
1.90 mm
|
65.6 mm
|
66.2 mm
|
5.50
|
53 mm
|
2.12 in.
|
2.12
|
1.60 mm
|
55.2 mm
|
55.7 mm
|
5.15
|
50 mm
|
2 in.
|
2
|
1.50 mm
|
52.1 mm
|
52.6 mm
|
5.05
|
45 mm
|
1 3/4 in.
|
1.75
|
1.40 mm
|
46.9 mm
|
47.4 mm
|
4.85
|
37.5 mm
|
1 1/2 in.
|
1.5
|
1.10 mm
|
39.1 mm
|
39.5 mm
|
4.59
|
31.5 mm
|
1 1/4 in.
|
1.25
|
1.00 mm
|
32.9 mm
|
33.2 mm
|
4.23
|
26.5 mm
|
1.06 in.
|
1.06
|
0.80 mm
|
27.7 mm
|
28.0 mm
|
3.90
|
25.0 mm
|
1 in.
|
1
|
0.80 mm
|
26.1 mm
|
26.4 mm
|
3.80
|
22.4 mm
|
|
0.875
|
0.70 mm
|
23.4 mm
|
23.7 mm
|
3.50
|
19.0 mm
|
3/4 in.
|
0.750
|
0.60 mm
|
19.9 mm
|
20.1 mm
|
3.30
|
16.0 mm
|
|
0.625
|
0.50 mm
|
16.7 mm
|
17.0 mm
|
3.00
|
13.2 mm
|
0.530 in.
|
0.530
|
0.41 mm
|
13.83 mm
|
14.05 mm
|
2.75
|
12.5 mm
|
1/2 in.
|
0.500
|
0.39 mm
|
13.10 mm
|
13.31 mm
|
2.67
|
11.2 mm
|
7/16 in.
|
0.438
|
0.35 mm
|
11.75 mm
|
11.94 mm
|
2.45
|
9.50 mm
|
|
0.375
|
0.30 mm
|
9.97 mm
|
10.16 mm
|
2.27
|
8.00 mm
|
5/16 in.
|
0.312
|
0.25 mm
|
8.41 mm
|
8.58 mm
|
2.07
|
6.70 mm
|
0.265 in.
|
0.265
|
0.21 mm
|
7.05 mm
|
7.20 mm
|
1.87
|
6.30 mm
|
1/4 in.
|
0.250
|
0.20 mm
|
6.64 mm
|
6.78 mm
|
1.82
|
5.60 mm
|
No. 3 1/2
|
0.223
|
0.18 mm
|
5.90 mm
|
6.04 mm
|
1.68
|
4.75 mm
|
No. 4
|
0.187
|
0.15 mm
|
5.02 mm
|
5.14 mm
|
1.54
|
4.00 mm
|
No. 5
|
0.157
|
0.13 mm
|
4.23 mm
|
4 35 mm
|
1.37
|
3.35 mm
|
No. 6
|
0.132
|
0.11 mm
|
3.55 mm
|
3.66 mm
|
1.23
|
2.80 mm
|
No. 7
|
0.11
|
0.095 mm
|
2.975 mm
|
3.070 mm
|
1.10
|
2.36 mm
|
No. 8
|
0.0937
|
0.080 mm
|
2.515 mm
|
2.600 mm
|
1.00
|
2.00 mm
|
No. 10
|
0.0787
|
0.070 mm
|
2.135 mm
|
2.215 mm
|
0.900
|
1.70 mm
|
No. 12
|
0.0661
|
0.060 mm
|
1.820 mm
|
1.890 mm
|
0.810
|
1.40 mm
|
No. 14
|
0.0555
|
0.050 mm
|
1.505 mm
|
1.565 mm
|
0.725
|
1.18 mm
|
No. 16
|
0.0469
|
0.045 mm
|
1.270 mm
|
1.330 mm
|
0.650
|
1.00 mm
|
No. 18
|
0.0394
|
0.040 mm
|
1.080 mm
|
1.135 mm
|
0.580
|
0.850 mm
|
No. 20
|
0.0331
|
0.035 mm
|
0.925 mm
|
0.970 mm
|
0.510
|
0.710 mm
|
No. 25
|
0.0278
|
0.030 mm
|
0.775 mm
|
0.815 mm
|
0.450
|
0.600 mm
|
No. 30
|
0.0234
|
0.025 mm
|
0.660 mm
|
0.695 mm
|
0.390
|
0.500 mm
|
No. 35
|
0.0197
|
0.020 mm
|
0.550 mm
|
0.585 mm
|
0.340
|
0.425 mm
|
No. 40
|
0.0165
|
0.019 mm
|
0.471 mm
|
0.502 mm
|
0.290
|
0.355 mm
|
No. 45
|
0.0139
|
0.016 mm
|
0.396 mm
|
0.425 mm
|
0.247
|
0.300 mm
|
No. 50
|
0.0117
|
0.014 mm
|
0.337 mm
|
0.363 mm
|
0.215
|
0.250 mm
|
No. 60
|
0.0098
|
0.012 mm
|
0.283 mm
|
0.306 mm
|
0.180
|
0.212 mm
|
No. 70
|
0.0083
|
0.010 mm
|
0.242 mm
|
0.263 mm
|
0.152
|
0.180 mm
|
No. 80
|
0.0070
|
0.009 mm
|
0.207 mm
|
0.227 mm
|
0.131
|
0.150 mm
|
No. 100
|
0.0059
|
0.008 mm
|
0.174 mm
|
0.192 mm
|
0.110
|
0.125 mm
|
No. 120
|
0.0049
|
0.007 mm
|
0.147 mm
|
0.163 mm
|
0.091
|
0.106 mm
|
No. 140
|
0.0041
|
0.006 mm
|
0.126 mm
|
0.141 mm
|
0.076
|
0.090 mm
|
No. 170
|
0.0035
|
0.005 mm
|
0.108 mm
|
0.122 mm
|
0.064
|
0.075 mm
|
No. 200
|
0.0029
|
0.005 mm
|
0.091 mm
|
0.103 mm
|
0.053
|
0.063 mm
|
No. 230
|
0.0025
|
0.004 mm
|
0.077 mm
|
0.089 mm
|
0.044
|
0.053 mm
|
No. 270
|
0.0021
|
0.004 mm
|
0.066 mm
|
0.076 mm
|
0.037
|
0.045 mm
|
No. 325
|
0.0017
|
0.003 mm
|
0.057 mm
|
0.066 mm
|
0.030
|
0.038 mm
|
No. 400
|
0.0015
|
0.003 mm
|
0.048 mm
|
0.057 mm
|
0.025
|
0.032 mm
|
No. 450
|
0.0012
|
0.003 mm
|
0.042 mm
|
0.050 mm
|
0.028
|
0.025 mm
|
No. 500
|
0.0010
|
0.003 mm
|
0.034 mm
|
0.041 mm
|
0.025
|
0.020 mm
|
No. 635
|
0.0008
|
0.003 mm
|
0.029 mm
|
0.035 mm
|
0.020
|
HARD CONVERSION FOR CONSTRUCTION MATERIALS
|
|||
Structural Steel, M270 | |||
Min. Tensile Strength
|
Min. Yield Strength
|
Min. Yield Strength
|
|
Grade |
(MPa)
|
(MPa)
|
(ksi)
|
36 |
400
|
250
|
36
|
50 |
450
|
345
|
50
|
50W |
485
|
345
|
50
|
70W |
620
|
480
|
70
|
Reinforcing Bars, M31M | ||||
Grade
|
Tensile and Yield Strengths
|
|||
Metric
|
English
|
Tensile Strength
|
Min. Yield Strength
|
Min. Yield Strength
|
Value
|
Value
|
(MPa)
|
(MPa)
|
(ksi)
|
300
|
40
|
500
|
300
|
40
|
400
|
60
|
600
|
400
|
60
|
Common Concrete Strengths (f'c) | |||||||
Metric | (MPa) | 20 | 28 | 35 | 43 | 48 | 55 |
English | (psi) | 3000 | 4000 | 5000 | 6000 | 7000 | 8000 |
Coefficient of Thermal Expansion | ||
Metric Value | English Value | |
Steel | 0.0000117/oC | 0.0000065/oF |
Concrete | 0.0000108/oC | 0.000006/oF |
Unit Weights | ||
Metric Value | English Value | |
Steel | 7848.3 kg/m3 | 490 pcf |
Concrete | 2402.5 kg/m3 | 150 pcf |
THE CONSTRUCTION TRADES
Here are the metric units that will be used by the construction trades. The term "length" includes all linear measurements--length, width, height, thickness, diameter, and circumference.
Quantity | Unit | Symbol | |
Surveying | |||
length | kilometer, meter | km, m | |
area | square kilometer | km2 | |
hectare (10,000 m2) | ha | ||
square meter | m2 | ||
plane angle | degree (non metric) | o | |
minute (non metric) | ' | ||
second (non metric) | " | ||
Excavating | |||
length | meter, millimeter | m, mm | |
volume | cubic meter | m3 | |
Trucking | |||
distance | kilometer | km | |
volume | cubic meter | m3 | |
mass | metric ton (1000 kg) | t | |
Paving | |||
length | meter, millimeter | m, mm | |
area | square meter | m2 | |
Concrete | |||
length | meter, millimeter | m, mm | |
area | square meter | m2 | |
volume | cubic meter | m3 | |
temperature | degree Celsius | oC | |
water capacity | liter (1000cm) | L | |
mass (weight) | kilogram, gram | kg, g | |
cross-sectional area | square millimeter | mm2 |
Pipe is one of the most ubiquitous products in construction. It is made of a wide variety of materials, including galvanized steel, black steel, copper, cast iron, concrete, and various plastics such as ABS, PVC, CPVC, polyethylene, and polybutylene, among others.
But like wood 2-by-4's which are not really 2 inches by 4 inches, pipe is identified by "nominal" or "trade" names that are related only loosely to actual dimensions. For instance, a 2-inch galvanized steel pipe has n inside diameter of about 2-1/8 inches and an outside diameter of about 2-5/8 inches. It is called "2-inch pipe" only for the sake of convenience.
Since few, if any, pipe products have actual dimensions that are in even, round inch-pound numbers, there is no need to convert them to even, round metric numbers. Instead, only their names will change--from inch-pound to metric. Pipe cross sections will not change. Fittings, flanges, couplings, valves, and other piping components will be renamed in like manner as will pipe threads. Here are the inch-pound names for pipe products (called NPS or "nominal pipe size") and their metric equivalents (called DN or "diameter nominal"). The metric names conform to International Standards Organization (ISO) usage and apply to all plumbing, natural gas, heating oil, drainage, and miscellaneous piping used in buildings and civil works projects.
NPS
|
DN
|
NPS
|
DN
|
1/8"
|
6 mm
|
8"
|
200 mm
|
3/16"
|
7 mm
|
10"
|
250 mm
|
1/4"
|
8 mm
|
12"
|
300 mm
|
3/8"
|
10 mm
|
14"
|
350 mm
|
1/2"
|
15 mm
|
16"
|
400 mm
|
5/8"
|
18 mm
|
18"
|
450 mm
|
3/4"
|
20 mm
|
20"
|
500 mm
|
1"
|
25 mm
|
24"
|
600 mm
|
1-1/4"
|
32 mm
|
28"
|
700 mm
|
1-1/2"
|
40 mm
|
30"
|
750 mm
|
2"
|
50 mm
|
32"
|
800 mm
|
2-1/2"
|
65 mm
|
36"
|
900 mm
|
3"
|
80 mm
|
40"
|
1000 mm
|
3-1/2"
|
90 mm
|
44"
|
1100 mm
|
4"
|
100 mm
|
48"
|
1200 mm
|
4-1/2"
|
115 mm
|
52"
|
1300 mm
|
5"
|
125 mm
|
56"
|
1400 mm
|
6"
|
150 mm
|
60"
|
1500 mm
|
**(For pipe over 60 inches, use 1 inch equals 25 mm)
TABLE 1 | |
PROPOSED METRIC CSP DIAMETER SIZES
|
|
Proposed Metric (mm)
|
Current Standard (inches)
|
150
|
6
|
200
|
8
|
250
|
10
|
300
|
12
|
375
|
15
|
450
|
18
|
525
|
21
|
600
|
24
|
675
|
27
|
750
|
30
|
825
|
33
|
900
|
36
|
1050
|
42
|
1200
|
48
|
1350
|
54
|
1500
|
60
|
1650
|
66
|
1800
|
72
|
1950
|
78
|
2100
|
84
|
2250
|
90
|
2400
|
96
|
2550
|
102
|
2700
|
108
|
2850
|
114
|
3000
|
120
|
3150
|
126
|
3300
|
132
|
3450
|
138
|
3600
|
144
|
TABLE 2 | |
Current (inches)
|
Corrugation Sizes Proposed (millimeters)
|
2 2/3 x 1/2
|
68 x 13
|
3 x 1
|
76 x 25
|
5 x 1
|
125 x 25
|
3/4 x 3/4 x 7 1/2
|
19 x 19 x 191
|
3/4 x 1 x 11 1/2
|
19 x 25 x 292
|
TABLE 3 | ||
PIPE WALL THICKNESS
|
||
Current
Gage |
Nominal Thickness
(inches) |
Proposed Nominal Thickness
(millimeters) |
16
|
0.064
|
1.6
|
14
|
0.079
|
2.0
|
12
|
0.109
|
2.8
|
10
|
0.138
|
3.5
|
8
|
0.168
|
4.3
|
TABLE 4 | |||
PIPE ARCH SIZES
|
|||
Corrugations
|
Corrugations
|
||
Inches
|
Millimeters
|
Inches
|
Millimeters
|
2 2/3 x 1/2
|
68 x 13
|
3 x 1 & 5 x 1
|
76 x 25 & 125 x 25
|
Span x Rise
|
Span x Rise
|
Span x Rise
|
Span x Rise
|
17 x 13
|
425 x 325
|
53 x 41
|
1325 x 1025
|
21 x 15
|
525 x 375
|
60 x 46
|
1500 x 1150
|
24 x 18
|
600 x 450
|
66 x 51
|
1650 x 1275
|
28 x 20
|
700 x 500
|
73 x 55
|
1825 x 1375
|
35 x 24
|
875 x 600
|
81 x 59
|
2025 x 1475
|
42 x 29
|
1050 x 725
|
87 x 63
|
2175 x 1575
|
49 x 33
|
1225 x 825
|
95 x 67
|
2375 x 1675
|
57 x 38
|
1425 x 950
|
103 x 71
|
2575 x 1775
|
64 x 43
|
1600 x 1075
|
112 x 75
|
2800 x 1875
|
71 x 47
|
1775 x 1175
|
117 x 79
|
2925 x 1975
|
77 x 52
|
1925 x 1300
|
128 x 83
|
3200 x 2075
|
83 x 57
|
2075 x 1425
|
137 x 87
|
3425 x 2175
|
142 x 91
|
3550 x 2275
|
||
Note: millimeters equal to inches x 25. Assumed pipe diameters will be x 25. |
TABLE 4A | |
PIPE ARCH SIZES
|
|
Corrugations
|
Corrugations
|
(inches)
|
(millimeters)
|
3/4 x 3/4 x 7 1/2
|
19 x 19 x 191
|
Span x Rise
|
Span x Rise
|
20 x 16
|
500 x 400
|
23 x 19
|
575 x 475
|
27 x 21
|
675 x 525
|
33 x 26
|
825 x 650
|
40 x 31
|
1000 x 775
|
46 x 36
|
1150 x 900
|
53 x 41
|
1325 x 1025
|
60 x 46
|
1500 x 1150
|
66 x 51
|
1650 x 1275
|
73 x 55
|
1825 x 1375
|
81 x 59
|
2025 x 1475
|
87 x 63
|
2175 x 1575
|
95 x 67
|
2375 x 1675
|
Note: millimeters equal to inches x 25. Assumed pipe diameters will be x 25. |
STRUCTURAL PLATE DIMENSIONS
|
|||
6 X 2 Corrugation
|
|||
31 Inch Corner Radius
|
|||
Span
|
Rise
|
R
|
R
|
ft-in
|
ft-in
|
ft.
|
ft.
|
13-3
|
9-4
|
6.68
|
16.05
|
14-11
|
10-2
|
7.48
|
18.98
|
16-6
|
11-0
|
8.29
|
21.93
|
18-1
|
11-10
|
9.09
|
24.98
|
19-8
|
12-8
|
9.90
|
28.04
|
TABLE 5M | |||
STRUCTURAL PLATE DIMENSIONS
|
|||
152 x 51 Corrugation
|
|||
787 mm Corner Radius
|
|||
(millimeters)
|
|||
Span
|
Rise
|
R
|
R
|
4039
|
2845
|
2036
|
4892
|
4547
|
3099
|
2280
|
5785
|
5029
|
3353
|
2527
|
6684
|
5512
|
3607
|
2771
|
7614
|
5994
|
3861
|
3018
|
8547
|
TABLE 6 | ||
STRUCTURAL PLATE THICKNESS
|
||
Current Specification
|
Proposed
|
|
Gage
|
Inches
|
Millimeters
|
12
|
.111
|
2.5
|
10
|
.140
|
3.5
|
8
|
.170
|
4.5
|
7
|
.188
|
-
|
5
|
.218
|
5.5
|
3
|
.249
|
6.5
|
1
|
.280
|
7.0
|
5/16
|
.318
|
8.0
|
3/8
|
.377
|
9.5
|