1、1The EverydayPocket Handbookon Metric Practicesfor the WeldingIndustryCompiled as a useful tool foron-the-job welding personnel by theAWS Product Development CommitteeNumber 5 in a series2NOTE: Although care was taken in choosing and presenting the data in this guide, AWS cannot guarantee that it is
2、error free. Further, this guide is not intended to be an exhaustive treatment of the topic and therefore may not include allavailable information, including with respect to safety and health issues. By publishing this guide, AWS does not insureanyone using the information it contains against any lia
3、bility or injury to property or persons arising from that use.Edited byLee G. Kvidhal, Manager,Welding and Manufacturing Engineering,Ingalls Shipbuilding, Pascagoula, MS 1997 by American Welding Society. All rights reservedPrinted in the United States of America3Why SI Units?4Table 1 SI Units.6Table
4、 2 Formulas for SI Derived Units .7Table 3 Units Pertaining to Welding .8Table 4 SI Prefixes 9Table 5 Conversions for Common Welding Terms.10Table 6 Length Conversions13Table 7 Electrode Sizes .15Table 8 Fillet Weld Sizes.15Table 9 Welding Travel and Wire Feed Speeds16Table 10 Deposition Rates.17Tab
5、le 11 Gas Flow Rates.18Table 12 Impact Energy 19Table 13 Pressure and Stress Equivalents .20Table 14 Temperature Conversions.21Table 15 Heat Input .22Table of Contents4This pocket handbook contains the accepted def-inition of the International System of Units (SI)as contained in the pertinent Americ
6、an NationalStandards Institute (ANSI) and InternationalStandards Organization (ISO) documents.The United States is one of the very few coun-tries left using the U.S. customary measurementsystem. The world is now a global market. Therewill be many more conversions to SI units asU.S. companies compete
7、 in the world market.SI is a modernized system of measurement. Itwas formally established in 1960 as the Interna-tional System of Units, and is officially recog-nized by all industrial nations. It has featuresthat make it superior to the U.S. customary sys-tem and to other metric systems. The advan-
8、tages to be derived from these features requirefamiliarity with the SI units to recognize thesimplicity of their usage.An absolute system has several advantages, thegreatest of which is simplicity of calculation.For example, in SI units, a force of one newtongives a mass of one kilogram an accelerat
9、ion ofone meter per second squared. Confusion arisesin the United States because the pound is usedfor either force or mass.Coherence is the characteristic that relates anyderived unit to any other, or to the base unitsfrom which it is formed, without the use of con-version factors. In SI units, a fo
10、rce of one new-ton applied through a distance of one meterdoes work equivalent to one joule, which equalsWhy SI Units?5the work produced by one watt of power in onesecond.Another desirable characteristic of SI is its useof only one unit for each physical quantity. TheSI units of force, energy and po
11、wer are the sameregardless of whether the process is mechanical,electrical or thermal. Power, whether in enginesor air conditioners, is measured in watts. Bycontrast, the U.S. customary system has ninecommonly used units for area, twenty-five unitsfor energy, twenty-six units for length, and soon.SI
12、 is a decimal system, and thus, easier to usebecause it is easier to work in multiples of tenand in decimal notation than in the fractions anddecimalized fraction equivalents common to thecustomary U.S. system.The above combination of features makes SI anexcellent system, suitable for all kinds of m
13、ea-surements. Though there remain areas that canand no doubt will be improved, SI is practicalfor universal application and is rapidly becom-ing the commonly used world measurementsystem.6Table 1SI UnitsSI consists of seven base units, two supplemental units, a series of derived units, and a series
14、of prefixes for theformation of multiples of the various units.Measure Unit Symbollength meter mmass kilogram kgtime second selectric current ampere Athermodynamic temperature kelvin Kluminous intensity candela cdamount of substance mole molplane angle1radian radsolid angle1steradian sr1supplementar
15、y units7Table 2Formulas for SI Derived UnitsMeasure Unit Symbol Formulaaccelerationlinearaccelerationangularmeter per second squaredradian per second squaredm/s2rad/s2area square meterm2capacitance farad F A s/Vconductivity (thermo) watt per meter kelvin W/(m K)electric field strength volt per meter
16、 V/melectromotive force volt V W/Aelectricity (quantity) coulomb C A senergy, work, heat, and impact strength joule J N mforce newton Nkg m/s2frequency hertz Hzs1illumination lux lxlm/m2inductance henry H V s/Aluminous flux lumen lm cd srmagnetic flux weber Wb V smagnetic flux density, magnetic indu
17、ction tesla TWb/m2power watt W J/spressure, stress pascal PaN/m2resistance ohm V/Avelocitylinearvelocityangularmeter per secondradian per secondm/srad/svolume cubic meterm3 8Table 3Units Pertaining to WeldingProperty Unit Symbolarea dimensions square millimeter mm2current density ampere per square m
18、illimeter A/mm2deposition rate kilogram per hour kg/helectrical resistivity ohm meter melectrode force newton Nflow rate (gas and liquid) liter per minute L/minfracture toughness meganewton meter3/2MN m3/2impact strength joule J = N mlinear dimensions millimeter mmpower density watt per square meter
19、 W/m2pressure (gas and liquid) kilopascal kPa = 1000 N/m2pressure (vacuum) pascal Pa = N/m2tensile strength megapascal MPa = 1 000 000 N/m2thermal conductivity watt per meter kelvin W/(m K)travel speed millimeter per second mm/svolume dimensions cubic millimeter mm3wire feed speed millimeter per sec
20、ond mm/s9Table 4SI PrefixesExponential Expression Multiplication Factor Prefix Symbol10181 000 000 000 000 000 000 exa E10151 000 000 000 000 000 peta P10121 000 000 000 000 tera T1091 000 000 000 giga G1061 000 000 mega M1031000 kilo k102100 hecto* h10 10 deka* da1010.1 deci* d1020.01 centi* c1030.
21、001 milli m1060.000 001 micro 1090.000 000 001 nano n10120.000 000 000 001 pico p10150.000 000 000 000 001 femto f10180.000 000 000 000 000 001 atto a*Nonpreferred. Prefixes should be selected in steps of 103.These prefixes should not be used for units of linear measurement, but may be used for high
22、er order units. For example, the linear measurement,decimeter, is nonpreferred, but square decimeter is acceptable.10Table 5Conversions for Common Welding Terms*Property To Convert From To Multiply Byarea dimensions(mm2)in.2mm2mm2in.26.451 600 1021.550 003 103current density(A/mm2)A/in2A/mm2A/mm2A/i
23、n.21.550 003 1036.451 600 102deposition rate(kg/h)lb/hkg/hkg/hlb/h0.435 924 1012.204 623electrical resistivity( m) cm m m cm1.000 000 1021.000 000 102electrical force(N)pound-forcekilogram-forceNNNlbf4.448 2229.806 6502.248 089 101flow rate(L/min)ft3/hgallon per hourgallon per minuteL/minL/minL/min4
24、.719 474 1016.309 020 1023.785 412fracture toughness(MN m3/2)ksi in.1/2MN m3/2MN m3/2ksi in.1/21.098 8439.100 477 101heat input(J/m)J/in.J/mJ/mJ/in.3.937 008 102.540 000 10211impact energy foot pound-force J 1.355 818linear measurements(mm)in.ftmmmmmmmmin.ft2.540 000 103.048 000 1023.937 008 1023.28
25、0 840 103power density(W/ m2)W/in.2W/m2W/m2W/in.21.550 003 1036.451 600 104pressure(gas and liquid)(kPa)psilbfft2N/mm2kPakPakPakPakPakPapsilbfft2N/mm26.894 7574.788 026 1021.000 000 1031.450 377 1012.088 543 101.000 000 103pressure(vacuum)(Pa)torr (mm Hg at 0C)micron (m Hg at 0C)PaPabarPaPatorrmicro
26、npsi1.333 224 1021.333 224 1017.500 617 1037.500 6171.450 377 101Table 5Conversions for Common Welding Terms* (Continued)Property To Convert From To Multiply By12tensile strength(MPa)psilbfft2N/mm2MPaMPaMPaMPaMPaMPapsilbfft2N/mm26.894 757 1034.788 026 1051.000 0001.450 377 1022.088 543 1041.000 000t
27、hermal conductivity(W/m K)cal/(cm s C) W/(m K) 4.186 800 102travel speed, R orwire feed speed (mm/s)in./minmm/smm/sin./min4.233 333 1012.362 205*Preferred units are given in parentheses.Table 5Conversions for Common Welding Terms* (Continued)Property To Convert From To Multiply By13Table 6Length Con
28、versions (inch to millimeter)Inch and Millimeter Decimal Equivalents of Fractions of an Inch1 in. = 25.4 mm. To convert in. to mm, multiply by 25.4. To convert mm to in., divide mm by 25.4.InchMillimeterInchMillimeterInchMillimeterFraction Decimal Fraction Decimal Fraction Decimal1/64 0.015 625 0.39
29、6 875 13/64 0.203 125 5.159 375 13/32 0.406 250 10.318 7501/32 0.031 250 0.793 750 7/32 0.218 750 5.556 250 7/16 0.437 500 11.112 5003/64 0.046 875 1.190 625 15/64 0.234 375 5.953 125 15/32 0.468 750 11.906 2501/16 0.062 500 1.587 500 1/4 0.250 000 6.350 000 1/2 0.500 000 12.700 0005/64 0.078 125 1.
30、984 375 17/64 0.265 625 6.746 875 9/16 0.562 500 14.287 5003/32 0.093 750 2.381 250 9/32 0.281 250 7.143 750 5/8 0.625 000 15.875 0007/64 0.109 375 2.778 125 19/64 0.296 875 7.540 625 11/16 0.687 500 17.462 5001/8 0.125 000 3.175 000 5/16 0.312 500 7.937 500 3/4 0.750 000 19.050 0009/64 0.140 625 3.
31、571 875 21/64 0.328 125 8.334 375 13/16 0.812 500 20.637 5005/32 0.156 250 3.968 750 11/32 0.343 750 8.731 250 7/8 0.875 000 22.225 00011/64 0.171 875 4.365 625 23/64 0.359 375 9.128 125 15/16 0.937 500 23.812 5003/16 0.187 500 4.762 500 3/8 0.375 000 9.525 000 1 1.000 000 25.400 000141-1/8 1.125 00
32、0 28.575 000 3-1/4 3.250 000 82.550 000 7-1/2 7.500 000 190.500 0001-1/4 1.250 000 31.750 000 3-1/2 3.500 000 88.900 000 8 8.000 000 203.200 0001-3/8 1.375 000 34.925 000 3-3/4 3.750 000 95.250 000 8-1/2 8.500 000 215.900 0001-1/2 1.500 000 38.100 000 4 4.000 000 101.600 000 9 9.000 000 228.600 0001
33、-5/8 1.625 000 41.275 000 4-1/4 4.250 000 107.950 000 9-1/2 9.500 000 241.300 0001-3/4 1.750 000 44.450 000 4-1/2 4.500 000 114.300 000 10 10.000 000 254.000 0001-7/8 1.875 000 47.625 000 4-3/4 4.750 000 120.650 000 10-1/2 10.500 000 266.700 0002 2.000 000 50.800 000 5 5.000 000 127.000 000 11 11.00
34、0 000 279.400 0002-1/4 2.250 000 57.150 000 5-1/2 5.550 000 139.700 000 11-1/2 11.500 000 292.100 0002-1/2 2.500 000 63.500 000 6 6.000 000 152.400 000 12 12.000 000 304.800 0002-3/4 2.750 000 69.850 000 6-1/2 6.500 000 165.100 000 12-1/2 12.500 000 317.500 0003 3.000 000 76.200 000 7 7.000 000 177.
35、800 000 13 13.000 000 330.200 000Table 6Length Conversions (inch to millimeter) (Continued)Inch and Millimeter Decimal Equivalents of Fractions of an Inch1 in. = 25.4 mm. To convert in. to mm, multiply by 25.4. To convert mm to in., divide mm by 25.4.InchMillimeterInchMillimeterInchMillimeterFractio
36、n Decimal Fraction Decimal Fraction Decimal15Table 7Electrode Sizes(Approximate Equivalents)in. mm0.030 0.80.035 0.90.040 1.00.045 1.11/16 1.65/64 2.03/32 2.41/80 3.25/32 4.03/16 4.81/40 6.4Table 8Fillet Weld Sizes(Approximate Equivalents)Fillet Size(Approximate Equivalents)Metric Fillet Size (Ratio
37、nal Series)1in. mm mm1/80 335/32 4 43/16 5 51/40 665/16 8 83/80 10 107/16 11 121/20 13 *5/80 16 163/40 19 20125 25*No value is required in this interval for rational sizing.1Rational size that would be selected for original design work ratherthan converting existing U.S. customary units.16Table 9Wel
38、ding Travel and Wire Feed Speeds (inches per minute to millimeters per second)1 in./min = 0.423 mm/s. To convert in./min to mm/s, multiply by 0.423. To convert mm/s to in./min, divide by 0.423.Find the number to be converted in the center (boldface) column. If converting mm/s, read the in./min equiv
39、alentin the column headed “in./min.” If converting in./min, read the mm/s equivalent in the column headed “mm/s.”mm/s in./min mm/s in./min mm/s in./min1.69 4 9.46 16.92 40 94.56 84.60 200 472.812.54 6 14.18 19.04 45 106.38 93.06 220 520.093.38 8 18.91 21.15 50 118.20 101.52 240 567.384.23 10 23.64 2
40、5.38 60 141.84 109.98 260 614.665.08 12 28.37 29.61 70 165.48 118.44 280 661.945.92 14 33.10 33.84 80 189.13 126.90 300 709.226.77 16 37.83 38.07 90 212.77 135.36 320 756.507.61 18 42.55 42.30 100 236.41 143.82 340 803.788.46 20 47.28 50.76 120 283.69 152.28 360 851.0610.58 25 59.10 59.22 140 330.97
41、 160.74 380 898.3412.69 30 70.92 67.68 160 378.25 169.20 400 945.6314.81 35 82.74 76.14 180 425.5317Table 10Deposition Rates (pounds per hour to kilograms per hour)1 lb/h = 0.45 kg/h. To convert lb/h to kg/h, multiply by 0.45. To convert kg/h to lb/h, divide by 0.45.Find the number to be converted i
42、n the center (boldface) column. If converting lb/h, read the kg/h equivalent inthe column headed “kg/h.” If converting kg/h, read the lb/h equivalent in the column headed “lb/h.”lb/h kg/h lb/h kg/h lb/h kg/h4.44 2 0.9 48.89 22 9.9 133.33 60 27.008.89 4 1.8 53.33 24 10.80 144.44 65 29.2513.33 6 2.7 5
43、7.78 26 11.70 155.56 70 31.5017.78 8 3.6 62.22 28 12.60 166.67 75 33.7522.22 10 4.5 66.67 30 13.50 177.78 80 36.0026.67 12 5.4 77.78 35 15.75 188.89 85 38.2531.11 14 6.3 88.89 40 18.00 200.00 90 40.5035.56 16 7.2 100.00 45 20.25 211.11 95 42.7540.00 18 8.1 111.11 50 22.50 222.22 100 45.0044.44 20 9.
44、0 122.22 55 24.7518Table 11Gas Flow Rates (cubic feet per hour to liters per minute)1 ft3/h = 0.4719 L/min. To convert ft3/h to L/min, multiply by 0.4719. To convert L/min to ft3/h, divide by 0.4719.Find the number to be converted in the center (boldface) column. If converting ft3/h, read the L/min
45、equivalent inthe column headed “L/min.” If converting L/min, read the ft3/h equivalent in the column headed “ft3/h.”ft3/h L/min ft3/h L/min8.5 4 1.9 59.3 28 13.212.7 6 2.8 63.6 30 14.217.0 8 3.8 67.8 32 15.121.2 10 4.7 72.0 34 16.025.4 12 5.7 76.3 36 17.029.7 14 6.6 80.5 38 17.933.9 16 7.6 84.8 40 1
46、8.938.1 18 8.5 89.0 42 19.842.4 20 9.4 93.2 44 20.846.6 22 10.4 97.5 46 21.750.9 24 11.3 101.70 48 22.755.1 26 12.3 106.00 50 23.619Table 12Impact Energy (foot pounds force to joules)1 ft lb = 1.356 J. To convert from ft lb to J, multiply by 1.356. To convert from J to ft lb, divide by 1.356.Find th
47、e number to be converted in the center (boldface) column. If converting ft lb, read the J equivalent in thecolumn headed “J.” If converting J, read the ft lb equivalent in the column headed “ft lb.”ft lb Jft lb J ft lb J3.687 5 6.780 22.124 30 40.680 41.298 56 75.9365.900 8 10.848 23.599 32 43.392 4
48、2.773 58 78.6487.375 10 13.560 25.074 34 46.104 44.248 60 81.3608.850 12 16.272 26.549 36 48.816 45.723 62 84.07210.324 14 18.984 28.024 38 51.528 47.198 64 86.78411.062 15 20.340 29.498 40 54.240 48.673 66 89.49611.799 16 21.696 30.973 42 56.952 50.147 68 92.20813.274 18 24.408 32.449 44 59.664 51.622 70 94.92014.749 20 27.120 33.923 46 62.376 53.097 72 97.63216.224 22 29.832 35.398 48 65.088 54.572 74 100.34417.699 24 32.544 36.873 50 67.800 56.047 76 103.05619.174 26 35.256 38.348 52 70.512 57.522 78 105.76820.649 28 37.968 39.823 54 73.224 58.997 80 108.480
