Core hole table

Core hole table for taps and thread formers

13

Through holeThrough holeThrough hole
Metric ISO standard threadMetric iISO finei threadUnified coari se thread
(M)i (MF)iii (UNC)i
d1PCore holeXd1PCore holed1PCore holed1Core holeX
MGBFormerXX
M 10.250.750.9M 20.251.75M 241231– 641.55
M 1.10.250.851.0M 2.20.251.95M 241.522.52– 561.85
M 1.20.250.951.1M 2.30.252.05M 242223– 482.1
M 1.40.31.11.28M 2.50.352.15M 251.523.54– 402.35
M 1.60,351.251.47M 2.60.352.25M 261.524.55– 402.65
M 1.70.351.351.57M 30.352.65M 271.525.56– 322.85
M 1.80.351.451.67M 3.50.353.15M 272258– 323.5
M 20.41.61.85M 40.353.65M 281.526.510– 243.9
M 2.20451752M 40535M 3012912– 2445
M 2.3. 0.4. 1.92.15M 5. 0.5. 4.5M 301.528.51/4 – 20. 5.1
M 2.5 M 2.60.45 0.452.05 2.152.3 2.4M 6 M 60.5 0.755.5 5.2M 30 M 322 1.528 30.55/16 – 18 3/8– 166.6 8
M 30.52.52.8M 70.756.2M 331.5317/16 – 149.4
M 3.50.62.93.25M 80.57.5M 332311/2– 1310.8
M 40.73.33.7M 80.757.2M 341.532.59/16 – 1212.2
M 4.50.753.84.2M 817M 351.533.55/8 – 1113.5
M 50.84.24.65M 918M 361.534.53/4– 1016.5
M 6155.55M 100.759.2M 362347/8 – 919.5
M 7166.6M 1019M 363331– 822.25
M 81.256.87.45M 101.258.8M 381.536.511/8 – 725
M 91.257.88.45M 11110M 3923711/4 – 728
M 101585935M 12111M 3933613/8– 63075
M 11. 1.5. 9.5. –M 121.2510.8M 401.538.511/2 – 6. 34
M 121.7510.211.20M 121.510.5M 4023813/4 – 539.5
M 1421213.00M 14113M 403372 – 445
M 1621415.00M 141.2512.8M 421.540.5
M 182.515.516.80M 141.512.5M 42240
M 202.517.518.80M 15114M 42339
M 222.519.5–M 151.513.5M 451.543.5
M 243212265M 16115M 45243
M 27324. –M 161.514.5M 45342Through hole
M 303.526.528.4M 18117M 481.546.5Whitworth pipe thread
M 3335295314M 1815165M 48246
M 36. 4. 32. 34.15M 18. 2. 16M 48345(G)
M 39435–M 20119M 501.548.5d PCore holeX
M 424.537.539.9M 201.518.5M 502481
M 454.540.542.9M 20218M 50347G 1⁄8 288.8
M 4854345.68M 22121M 521.550.5G 1⁄4 19 311.8
M 52547–M 221.520.5M 52250G ⁄8 1915.25
M 22220M 52349G 1⁄2 1419
G 5⁄8 14 G 3⁄4 1421 24.5
G7⁄8 1428.25
G 1 1130.75
Through holeThrough holeG 11⁄8 1135.5
G 11⁄4 1139.5
Whitworth threadUnified fine ti i hreadG 13⁄8 1142
(BSW)i i (UNF)i iG 11⁄2 1145
G 13⁄4 1151
d1PCore holeXd1Core holeXG 2 11 G 21⁄4 1157 631
W 1⁄16601.20– 801.25G 21⁄2 11. 72.6
W 3⁄32481.91– 721.55G 23⁄4 1178.9
W 1⁄8402.52– 641.9G 3 1185.3
Through holeThrough holeG 11⁄41139.5
Whitworth threadUnified fini ie threadG 13⁄8 G 11⁄11 1142 45
(BSW)(UNF)2 G 13⁄41151
d1PCore holeXd1Core holeXG 2 G 21⁄411 1157 63.1
W 1⁄16601.20– 801.25G 21⁄21172.6
W 3⁄32481.91– 721.55G 23⁄41178.9
W 1⁄8402.52– 641.9G 31185.3
W 5⁄32323.23– 562.15
W 3⁄16243.64– 482.4
W 7⁄32244.55– 442.7
W 1⁄4205.16– 402.95
W 5⁄16186.58– 363.5
W 3/8167.910– 324.1Through holeThrough hole
W 7⁄16149.2512– 284.7American tapered pipeSteel armoured pipe thread
W 1⁄21210.51⁄4– 285.5
W 9⁄1612125⁄16 – 246.9thread(NPT)(PG)
W 5⁄81113.53⁄8– 248.5
W 3⁄41016.57⁄16 – 209.9d1PCore holeXd1PCore holeX
W 7⁄8919.251⁄2 – 2011.51⁄16276.3Pg 72011.4
W 18229⁄16 – 1812.91⁄8278.5Pg 91814
W 11⁄8724.755⁄8 – 1814.51⁄41811.1Pg 111817.25
W 11⁄47283⁄4 – 1617.53⁄81814.5Pg 13.51819
W 13⁄8630.57⁄8 – 1420.41⁄21417.75Pg 161821.25
W 11⁄2633.51– 1223.253⁄41423Pg 211627
W 15⁄8535.511⁄8 – 1226.5111.529Pg 291635.5
W 13⁄453911⁄4 – 1229.5511⁄411.538Pg 361645.5
W 17⁄841⁄241.513⁄8 – 1232.7511⁄211.544Pg 421652.5
W 241⁄244.511⁄2 – 1236.0211.556Pg 481658
P = threads per inchP = threads per inchP = threads per inch