Threads
M
| Tap Size | Drill Size |
|---|---|
| M1.6 x 0.35 | 1.25mm |
| M2 x 0.4 | 1/16 |
| M2.5 x 0.45 | 2.05mm |
| M3 x 0.5 | #40 |
| M3 x 0.6 | 2.5mm |
| M3.5 x 0.6 | #33 |
| M4 x 0.7 | 3.3mm |
| M4 x 0.75 | 3.4mm |
| M5 x 0.8 | 4.2mm |
| M5 x 0.9 | 4.2mm |
| M6 x 1 | 5mm |
| M6.3 x 1 | 5.5mm |
| M7 x 1 | 6.1mm |
| M8 x 1 | 7.1mm |
| M8 x 1.25 | 6.7mm |
| M9 x 0.75 | 8.3mm |
| M9 x 1 | 8.1mm |
| M9 x 1.25 | 7.9mm |
| M10 x 1 | 9.1mm |
| M10 x 1.25 | 8.9mm |
| M10 x 1.5 | 8.4mm |
| M11 x 1.50 | 9.7mm |
| M12 x 1.25 | 10.9mm |
| M12 x 1.5 | 10.7mm |
| M12 x 1.75 | 13/32 |
| M14 x 1.25 | 12.8mm |
| M14 x 1.5 | 12.7mm |
| M14 x 2 | 15/32 |
| M16 x 1.5 | 14.7mm |
| M16 x 2 | 35/64 |
| M18 x 1.5 | 16.8mm |
| M18 x 2.5 | 15.8mm |
| M20 x 2.5 | 11/16 |
| M22 x 1.5 | 20.9mm |
| M24 x 2 | 22.3mm |
| M24 x 3 | 53/64 |
| M30 x 3.5 | 1-3/64 |
| M36 x 4 | 1-1/4 |
BA
| Screw Numbers | Diameter of Screw Over Thread |
Threads per inch | Pitch | Diameter at Thread Bottom |
Tapping Drill Size |
|---|---|---|---|---|---|
| 16 BA | 0.0310 inch | 133.3 tpi | 0.0075 inch | 0.0220 inch | Number drill 73 0.6 mm 0.0236 inch |
| 15 BA | 0.035 inch | 120.5 tpi | 0.0083 inch | 0.025 inch | Number drill 70 0.7 mm 0.0276 inch |
| 14 BA | 0.039 inch | 109.9 tpi | 0.0091inch | 0.028 inch | 0.8 mm 0.0315 inch |
| 13 BA | 0.047 inch | 102 tpi | 0.0098 inch | 0.0352 inch | Number drill 62 0.98 mm 0.0386 inch |
| 12 BA | 0.051 inch | 90.9 tpi | 0.011 inch | 0.0378 inch | Number drill 60 1.05 mm 0.0413 inch |
| 11 BA | 0.059 inch | 81.9 tpi | 0.0122 inch | 0.0443 inch | Number drill 56 1.2 mm 0.0472 inch |
| 10 BA | 0.067 inch | 72.6 tpi | 0.0138 inch | 0.0504 inch | Number drill 54 1.4 mm 0.0551 inch |
| 9 BA | 0.075 inch | 65.1 tpi | 0.0154 inch | 0.0565 inch | 1.55 mm 0.061 inch |
| 8 BA | 0.086 inch | 59.1 tpi | 0.0169 inch | 0.0657 inch | Number drill 50 1.8 mm 0.0709 inch |
| 7 BA | 0.0982 inch | 52.9 tpi | 0.0189 inch | 0.0753 inch | Number drill 46 2.05 mm 0.0807 inch |
| 6 BA | 0.11 inch | 47.9 tpi | 0.0209 inch | 0.0849 inch | 2.3 mm 0.0906 inch |
| 5 BA | 0.126 inch | 43 tpi | 0.0232 inch | 0.0981 inch | Number drill 37 2.65 mm 0.1043 inch |
| 4 BA | 0.1420 inch | 38.5 tpi | 0.0260 inch | 0.1108 inch | Number drill 31 3 mm 0.1181 inch |
| 3 BA | 0.1610 inch | 34.8 tpi | 0.0287 inch | 0.1266 inch | Number drill 29 3.4 mm 0.1339 inch |
| 2 BA | 0.1850 inch | 31.4 tpi | 0.0319 inch | 0.1467 inch | Number drill 22 4 mm 0.1575 inch |
| 1 BA | 0.2090 inch | 28.2 tpi | 0.0354 inch | 0.1665 inch | Number drill 16 4.5 mm 0.1772 inch |
| 0 BA | 0.2360 inch | 25.4 tpi | 0.0394 inch | 0.1887 inch | Number drill 9 5.1 mm 0.2008 inch |