Machine screws are used with nuts or screwed directly into a threaded receptacle to fasten parts together. Measured from the underside of the head to the tip of the screw to obtain fastener length. Use with nuts of the same finish and threaded.
| Screw Thread d | M3 | (M3.5) | M4 | M5 | M6 | M8 | |
| P | Pitch | 0.5 | 0.6 | 0.7 | 0.8 | 1 | 1.25 |
| a | max | 1 | 1.2 | 1.4 | 1.6 | 2 | 2.5 |
| b | min | 25 | 38 | 38 | 38 | 38 | 38 |
| dc | max=nominal size | 7.5 | 9 | 10 | 11.5 | 14.5 | 19 |
| min | 6.92 | 8.42 | 9.42 | 10.8 | 13.8 | 18.16 | |
| k | max=nominal size | 2.35 | 2.6 | 3.05 | 3.55 | 4.55 | 5.9 |
| min | 2.1 | 2.35 | 2.75 | 3.25 | 4.25 | 5.6 | |
| h | max | 0.8 | 0.9 | 1.1 | 1.35 | 1.8 | 2.2 |
| min | 0.6 | 0.7 | 0.9 | 1.05 | 1.4 | 1.8 | |
| x | max | 1.25 | 1.5 | 1.75 | 2 | 2.5 | 3.2 |
| Socket No. | 1 | 2 | 2 | 2 | 3 | 4 | |
| M1 | Ref. | 3 | 4.2 | 4.6 | 5 | 7.1 | 9 |
| M2 | Ref. | 2.9 | 3.9 | 4.3 | 4.7 | 6.7 | 8.8 |