BS 4168 Hexagon Socket Countersunk Head Screws
| Nom. Sizea | Body Diameter, D | Head Diameter, A | Head Height, H | Hexagon Socket Size, J | Key Engagement, K | Fillet Radius, F | |||
|---|---|---|---|---|---|---|---|---|---|
| Max. | Min. | Theor. Sharp Max. | Absolute Min. | Ref. | Flushness Tolerance | Nom. | Min. | Max. | |
| BS 4168 - M3 | 3 | 2.86 | 6.72 | 5.82 | 1.86 | 0.2 | 2 | 1.05 | 0.4 |
| BS 4168 - M4 | 4 | 3.82 | 8.96 | 7.78 | 2.48 | 0.2 | 2.5 | 1.49 | 0.4 |
| BS 4168 - M5 | 5 | 4.82 | 11.2 | 9.78 | 3.1 | 0.2 | 3 | 1.86 | 0.4 |
| BS 4168 - M6 | 6 | 5.82 | 13.44 | 11.73 | 3.72 | 0.2 | 4 | 2.16 | 0.6 |
| BS 4168 - M8 | 8 | 7.78 | 17.92 | 15.73 | 4.96 | 0.24 | 5 | 2.85 | 0.7 |
| BS 4168 - M10 | 10 | 9.78 | 22.4 | 19.67 | 6.2 | 0.3 | 6 | 3.6 | 0.8 |
| BS 4168 - M12 | 12 | 11.73 | 26.88 | 23.67 | 7.44 | 0.36 | 8 | 4.35 | 1.1 |
| BS 4168 - M14 | 14 | 13.73 | 30.24 | 26.67 | 8.12 | 0.4 | 10 | 4.65 | 1.1 |
| BS 4168 - M16 | 16 | 15.73 | 33.6 | 29.67 | 8.8 | 0.45 | 10 | 4.89 | 1.1 |
| BS 4168 - M18 | 18 | 17.73 | 36.96 | 32.61 | 9.48 | 0.5 | 12 | 5.25 | 1.1 |
| BS 4168 - M20 | 20 | 19.67 | 40.32 | 35.61 | 10.16 | 0.54 | 12 | 5.45 | 1.1 |
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