Metric Thread Gages ANSI / ASME B1.13M, METRIC SCREW THREADS–M PROFILE Standard Pitch Diameter Chart NOMINAL SIZE & PITCH FOR EXTERNAL THREADFOR INTERNAL THREAD PITCH DIAMETER GO RING GAGE 6g TOLERANCE PITCH DIAMETER NOT GO RING GAGE 6g TOLERANCE PITCH DIAMETER GO PLUG GAGE 6H TOLERANCE PITCH DIAMETER NOT GO PLUG GAGE 6H TOLERANCE MMIN. (REF)MMIN. (REF) MMIN. (REF) MMIN. (REF) M1.6 X 0.351.354.053311.291.050831.373.054061.458.05740 M2 X 0.41.721.067761.654.065121.740.068501.830.07205 M2.5 X 0.452.188.086142.117.083352.208.086932.303.09067 M3 X 0.52.655.104532.580.101572.675.105312.775.10925 M3.5 X 0.63.089.121613.004.118273.110.122443.222.12685 M4 X 0.73.523.138703.433.135163.545.139573.663.14421 M5 X 0.84.456.175434.361.171694.480.176384.605.18130 M6 X 1.05.324.209615.212.205205.350.210635.500.21654 M8 X 1.257.160.281897.042.277247.188.282997.348.28929 M8 X 1.07.324.288357.212.283947.350.289377.500.29528 M10 X 1.58.994.354098.862.348909.026.355359.206.36244 M10 X 1.259.160.360639.042.355989.188.361739.348.36803 M10 X 1.09.324.367099.212.362689.350.368119.500.37402 M10 X 0.759.491.373669.391.369729.513.374539.645.37972 M12 X 1.7510.829.4263410.679.4204310.863.4276811.063.43555 M12 X 1.510.994.4328310.854.4273211.026.4340911.216.44157 M12 X 1.2511.160.4393711.028.4341711.188.4404711.368.44756 M12 X 1.011.324.4458311.206.4411811.350.4468511.510.45315 M14 X 2.012.663.4985412.503.4922412.701.5000412.913.50839 M14 X 1.512.994.5115712.854.5060613.026.5128313.216.52031 M15 X 1.014.324.5639414.206.5592914.350.5649614.510.57126 M16 X 2.014.663.5772814.503.5709814.701.5787814.913.58713 M16 X 1.514.994.5903114.854.5848015.026.5915715.216.59906 M17 X 1.016.324.6426816.206.6380316.350.6437016.510.65000 M18 X 1.516.994.6690616.854.6635417.026.6703117.216.67780 M20 X 2.518.334.7218118.164.7151218.376.7234618.600.73228 M20 X 1.518.994.7478018.854.7422819.026.7490619.216.75654 M20 X 1.019.324.7607919.206.7561419.350.7618119.510.76811 M22 X 2.520.334.8005520.164.7938620.376.8022020.600.81102 M22 X 1.520.994.8265420.854.8210221.026.8278021.216.83528 M24 X 3.022.003.8662621.803.8583922.051.8681522.316.87858 M24 X 2.022.663.8922422.493.8855522.701.8937422.925.90256 M25 X 1.523.994.9446523.844.9387424.026.9459124.226.95378 M27 X 3.025.003.9843724.803.9765025.051.9862625.316.99669 M27 X 2.025.6631.0103525.4931.0036625.7011.0118525.9251.02067 M30 X 3.527.6741.0895327.6421.0811827.7271.0916128.0071.10264 M30 X 2.028.6631.1284628.4931.1217728.7011.1299628.9251.13878 M30 X 1.528.9941.1415028.8441.1355929.0261.1427629.2261.15063 M33 X 2.031.6631.2465731.4931.2398831.7011.2480731.9251.25689 M35 X 1.533.9941.3383533.8441.3324434.0261.3396134.2261.34748 M36 X 4.033.3421.3126833.1181.3038633.4021.3150433.7021.32685 M36 X 2.034.6631.3646934.4931.3579934.7011.3661834.9251.37500 M39 X 2.037.6631.4828037.4931.4761037.7011.4842937.9251.49311 8 0 0 . 2 3 2 . 4 2 4 3 P R E C I S I O N G A G E S F O R Q U A L I T Y A S S U R A N C E Standard Pitch Diameter Chart Plug Thread Gages NOMINAL SIZE GO BASIC ALL CLASSES ALL SERIES UNIFIED PITCH DIAMETERS NOT GO X TOL. GO =+ NO GO =– X LEAD TOL. X ± HALF ANGLE TOL. CL.ASS 2BCLASS 3B #0-80 UNF.0519.0542.0536.0002.00020°30' #1-64 UNC.0629.0655.0648.0002.00020°30' #1-72 UNF.0640.0665.0659.0002.00020°30' #2-56 UNC.0744.0772.0765.0002.00020°30' #2-64 UNF.0759.0786.0779.0002.00020°30' #3-48 UNC.0855.0885.0877.0002.00020°30' #3-56 UNF.0874.0902.0895.0002.00020°30' #4-40 UNC.0958.0991.0982.0002.00020°20' #4-48 UNF.0985.1016.1008.0002.00020°30' #5-40 UNC.1088.1121.1113.0002.00020°20' #5-44 UNF.1102.1134.1126.0002.00020°20' #6-32 UNC.1177.1214.1204.0003.00030°15' #6-40 UNF.1218.1252.1243.0002.00020°20' #8-32 UNC.1437.1475.1465.0003.00030°15' #8-36 UNF.1460.1496.1487.0002.00020°20' #10-24 UNC.1629.1672.1661.0003.00030°15' #10-32 UNF.1697.1736.1726.0003.00030°15' #12-24 UNC.1889.1933.1922.0003.00030°15' #12-28 UNF.1928.1970.1959.0003.00030°15' #12-32 UNEF.1957.1998.1988.0003.00030°15' 1⁄4-20 UNC .2175.2224.2211.0003.00030°15' 1⁄4-28 UNF .2268.2311.2300.0003.00030°15' 1⁄4-32 UNEF .2297.2339.2328.0003.00030°15' 5⁄16-18 UNC .2764.2817.2803.0003.00030°10' 5⁄16-24 UNF .2854.2902.2890.0003.00030°15' 5⁄16-32 UNEF .2922.2964.2953.0003.00030°15' 3⁄8-16 UNC .3344.3401.3387.0003.00030°10' 3⁄8-24 UNF .3479.3528.3516.0003.00030°15' 3⁄8-32 UNEF .3547.3591.3580.0003.00030°15' 7⁄16-14 UNC .3911.3972.3957.0003.00030°10' 7⁄16-20 UNF .4050.4104.4091.0003.00030°15' 7⁄16-28 UNEF .4143.4189.4178.0003.00030°15' 1⁄2-13 UNC .4500.4565.4548.0003.00030°10' 1⁄2-20 UNF .4675.4731.4717.0003.00030°15' 1⁄2-28 UNEF .4768.4816.4804.0003.00030°15' 9⁄16-12 UNC .5084.5152.5135.0003.00030°10' 9⁄16-18 UNF .5264.5323.5308.0003.00030°10' NOMINAL SIZE GO BASIC ALL CLASSES ALL SERIES UNIFIED PITCH DIAMETERS NOT GO X TOL. GO =+ NO GO =– X LEAD TOL. X ± HALF ANGLE TOL. CL.ASS 2BCLASS 3B 9⁄16-24 UNEF .5354.5405.5392.0003.00030°15' 5⁄8-11 UNC .5660.5732.5714.0003.00030°10' 5⁄8-18 UNF .5889.5949.5934.0003.00030°10' 5⁄8-24 UNEF .5979.6031.6018.0003。