
| Through hole | Through hole | Through hole | |||||||||
| Metric I | SO sta | ndard threa | d | Metric i | ISO fine | i thread | Unified coar | i se thread | |||
| (M) | i (MF) | i | i | i (UNC) | i | ||||||
| d1 | P | Core hol | eX | d1 | P | Core hole | d1 | P | Core hole | d1 | Core holeX |
| 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 | 045 | 175 | 2 | M 4 | 05 | 35 | M 30 | 1 | 29 | 12– 24 | 45 |
| 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 M 2.6 | 0.45 0.45 | 2.05 2.15 | 2.3 2.4 | M 6 M 6 | 0.5 0.75 | 5.5 5.2 | M 30 M 32 | 2 1.5 | 28 30.5 | 5/16 – 18 3/8– 16 | 6.6 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 | 15 | 85 | 935 | M 12 | 1 | 11 | M 39 | 3 | 36 | 13/8– 6 | 3075 |
| 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 | 2265 | M 16 | 1 | 15 | M 45 | 2 | 43 | ||
| M 27 | 3 | 24 | . – | M 16 | 1.5 | 14.5 | M 45 | 3 | 42 | Through hole | |
| M 30 | 3.5 | 26.5 | 28.4 | M 18 | 1 | 17 | M 48 | 1.5 | 46.5 | Whitworth pi | pe thread |
| M 33 | 35 | 295 | 314 | M 18 | 15 | 165 | M 48 | 2 | 46 | ||
| M 36 | . 4 | . 32 | . 34.15 | M 18 | . 2 | . 16 | M 48 | 3 | 45 | (G) | |
| M 39 | 4 | 35 | – | M 20 | 1 | 19 | M 50 | 1.5 | 48.5 | d P | Core holeX |
| M 42 | 4.5 | 37.5 | 39.9 | M 20 | 1.5 | 18.5 | M 50 | 2 | 48 | 1 | |
| 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 3 | 11.8 |
| M 52 | 5 | 47 | – | M 22 | 1.5 | 20.5 | M 52 | 2 | 50 | G ⁄8 19 | 15.25 |
| M 22 | 2 | 20 | M 52 | 3 | 49 | G 1⁄2 14 | 19 | ||||
| G 5⁄8 14 G 3⁄4 14 | 21 24.5 | ||||||||||
| G7⁄8 14 | 28.25 | ||||||||||
| G 1 11 | 30.75 | ||||||||||
| Through hole | Through hole | G 11⁄8 11 | 35.5 | ||||||||
| G 11⁄4 11 | 39.5 | ||||||||||
| Whitwo | rth thre | ad | Unified fine t | i i hread | G 13⁄8 11 | 42 | |||||
| (BSW) | i i (UNF) | i i | G 11⁄2 11 | 45 | |||||||
| G 13⁄4 11 | 51 | ||||||||||
| d1 | P | Core holeX | d1 | Core hol | eX | G 2 11 G 21⁄4 11 | 57 631 | ||||
| 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 | G 3 11 | 85.3 |
| Through hole | Through hole | G 11⁄4 | 11 | 39.5 | ||||||
| Whitwo | rth th | read | Unified fin | i ie thread | G 13⁄8 G 11⁄ | 11 11 | 42 45 | |||
| (BSW) | (UNF) | 2 G 13⁄4 | 11 | 51 | ||||||
| d1 | P | Core holeX | d1 | Core holeX | G 2 G 21⁄4 | 11 11 | 57 63.1 | |||
| 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 | G 3 | 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 | 9.25 | 12– 28 | 4.7 | Americ | an tap | ered pipe | Steel ar | mour | ed pipe thread |
| W 1⁄2 | 12 | 10.5 | 1⁄4– 28 | 5.5 | ||||||
| W 9⁄16 | 12 | 12 | 5⁄16 – 24 | 6.9 | thread | (NPT) | (PG) | |||
| W 5⁄8 | 11 | 13.5 | 3⁄8– 24 | 8.5 | ||||||
| W 3⁄4 | 10 | 16.5 | 7⁄16 – 20 | 9.9 | d1 | P | Core holeX | d1 | P | Core holeX |
| W 7⁄8 | 9 | 19.25 | 1⁄2 – 20 | 11.5 | 1⁄16 | 27 | 6.3 | Pg 7 | 20 | 11.4 |
| W 1 | 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 |
| W 2 | 41⁄2 | 44.5 | 11⁄2 – 12 | 36.0 | 2 | 11.5 | 56 | Pg 48 | 16 | 58 |
| P = t | hreads per inch | P = thre | ads per inch | P = th | reads per inch |