Taps Core hole table Product information Core hole table for taps and thread formers 13 Through hole Through hole Through hole Metric ISO standard thread Metric ISO fine thread Unified coarse thread (M) (MF) (UNC) d1 P Core hole X d1 P Core hole d1 P Core hole d1 Core hole X MGB Former X X M 1 0.25  0.75  0.9 M 2 0.25   1.75 M 24 1 23 1 – 64   1.55 M   1.1 0.25  0.85  1.0 M   2.2 0.25   1.95 M 24 1.5 22.5 2 – 56   1.85 M   1.2 0.25  0.95  1.1 M   2.3 0.25   2.05 M 24 2 22 3 – 48   2.1 M   1.4 0.3  1.1  1.28 M   2.5 0.35   2.15 M 25 1.5 23.5 4 – 40   2.35 M   1.6 0,35  1.25  1.47  M   2.6 0.35   2.25 M 26 1.5 24.5 5 – 40   2.65 M   1.7 0.35  1.35  1.57 M 3 0.35   2.65 M 27 1.5 25.5 6 – 32   2.85 M   1.8 0.35  1.45  1.67 M   3.5 0.35   3.15 M 27 2 25 8 – 32   3.5 M 2 0.4  1.6  1.85 M 4 0.35   3.65 M 28 1.5 26.5 10 – 24   3.9 M   2.2 0.45  1.75  2 M 4 0.5   3.5 M 30 1 29 12 – 24   4.5 M   2.3 0.4  1.9  2.15 M 5 0.5   4.5 M 30 1.5 28.5 1/4 – 20   5.1 M   2.5 0.45  2.05  2.3 M 6 0.5   5.5 M 30 2 28 5/16 – 18   6.6 M   2.6 0.45  2.15  2.4 M 6 0.75   5.2 M 32 1.5 30.5 3/8 – 16  8 M 3 0.5  2.5  2.8 M 7 0.75   6.2 M 33 1.5 31 7/16 – 14   9.4 M   3.5 0.6  2.9  3.25 M 8 0.5   7.5 M 33 2 31 1/2 – 13 10.8 M 4 0.7  3.3  3.7 M 8 0.75   7.2 M 34 1.5 32.5 9/16 – 12 12.2 M   4.5 0.75  3.8  4.2 M 8 1  7 M 35 1.5 33.5 5/8 – 11 13.5 M 5 0.8  4.2  4.65 M 9 1  8 M 36 1.5 34.5 3/4 – 10 16.5 M 6 1  5  5.55 M 10 0.75   9.2 M 36 2 34 7/8 – 9 19.5 M 7 1  6  6.6 M 10 1  9 M 36 3 33 1–8 22.25 M 8 1.25  6.8  7.45 M 10 1.25   8.8 M 38 1.5 36.5 11/8 – 7 25 M 9 1.25  7.8  8.45 M 11 1 10 M 39 2 37 11/4 – 7 28 M 10 1.5  8.5  9.35 M 12 1 11 M 39 3 36 13/8 – 6 30.75 M 11 1.5  9.5 – M 12 1.25 10.8 M 40 1.5 38.5 11/2 – 6 34 M 12 1.75 10.2 11.20 M 12 1.5 10.5 M 40 2 38 13/4 – 5 39.5 M 14 2 12 13.00 M 14 1 13 M 40 3 37 2–4 45 M 16 2 14 15.00 M 14 1.25 12.8 M 42 1.5 40.5 M 18 2.5 15.5 16.80 M 14 1.5 12.5 M 42 2 40 M 20 2.5 17.5 18.80 M 15 1 14 M 42 3 39 M 22 2.5 19.5 – M 15 1.5 13.5 M 45 1.5 43.5 M 24 3 21 22.65 M 16 1 15 M 45 2 43 Through hole M 27 3 24 – M 16 1.5 14.5 M 45 3 42 M 30 3.5 26.5 28.4 M 18 1 17 M 48 1.5 46.5 Whitworth pipe thread M 33 3.5 29.5 31.4 M 18 1.5 16.5 M 48 2 46M 3643234.15M 18216M 48345(G) M 39 4 35 – M 20 1 19 M 50 1.5 48.5M 424.537.539.9M 201.518.5M 50248d1 P* Core hole X M 45 4.5 40.5 42.9 M 20 2 18 M 50 3 47 G   1⁄8 28  8.8 M 48 5 43 45.68 M 22 1 21 M 52 1.5 50.5 G   1⁄4 19 11.8 M 52 5 47 – M 22 1.5 20.5 M 52 2 50 G   3⁄8 19 15.25 M 22 2 20 M 52 3 49 G   1⁄2 14 19 G   5⁄8 14 21 G   3⁄4 14 24.5 G   7⁄8 14 28.25 G1 11 30.75 Through hole Through hole G 11⁄8 11 35.5G 11⁄41139.5 Whitworth thread Unified fine thread G 13⁄8 11 42 (BSW) (UNF) G 11⁄2 11 45G 13⁄41151 d1 P* Core hole X d1 Core hole X G2 11 57G 21⁄41163.1 W   1⁄16 60  1.2  0 – 80  1.25 G 21⁄2 11 72.6 W   3⁄32 48  1.9  1 – 72  1.55 G 23⁄4 11 78.9 W   1⁄8 40  2.5  2 – 64  1.9 G3 11 85.3 W   5⁄32 32  3.2  3 – 56  2.15 W   3⁄16 24  3.6  4 – 48  2.4 W   7⁄32 24  4.5  5 – 44  2.7 W   1⁄4 20  5.1  6 – 40  2.95 W   5⁄16 18  6.5  8 – 36  3.5 W   3/8 16  7.9 10 – 32  4.1 Through hole Through hole W   7⁄16 14  9.25W   1⁄21210.5W   9⁄16121212 – 28  4.71⁄4 – 28 5.55⁄16 – 24 6.9American tapered pipe Steel armoured pipe threadthread (NPT)(PG) W   5⁄8 11 13.5W   3⁄41016.5 3⁄8 – 24  8.57⁄16 – 20 9.9 d1 P* Core hole X d1 P* Core hole X W   7⁄8  9 19.25 1⁄2 – 20 11.5   1⁄16 27  6.3 Pg   7 20 11.4 W1  8 22 9⁄16 – 18 12.9   1⁄8 27  8.5 Pg   9 18 14 W 11⁄8  7 24.75 5⁄8 – 18 14.5   1⁄4 18 11.1 Pg   11 18 17.25 W 11⁄4  7 28 3⁄4 – 16 17.5   3⁄8 18 14.5 Pg   13.5 18 19 W 13⁄8  6 30.5 7⁄8 – 14 20.4   1⁄2 14 17.75 Pg   16 18 21.25 W 11⁄2  6 33.5 1 – 12 23.25   3⁄4 14 23 Pg   21 16 27 W 15⁄8  5 35.5 11⁄8 – 12 26.5 1 11.5 29 Pg   29 16 35.5 W 13⁄4  5 39 11⁄4 – 12 29.55 11⁄4 11.5 38 Pg   36 16 45.5 W 17⁄8  41⁄2 41.5 13⁄8 – 12 32.75 11⁄2 11.5 44 Pg   42 16 52.5 W2  41⁄2 44.5 11⁄2 – 12 36.0 2 11.5 56 Pg   48 16 58 P* = threads per inch P* = threads per inch P* = threads per inch 13/156 www.precitool.de