Alloy steel heat treated cup point hex socket set screws. These are designed for maximum holding capacity and are made of hardened steel.
| Size | Hex Key Required |
| 0-80 | 0.028 |
| 1-72 | 0.035 |
| 2-56 | 0.035 |
| 3-48 | 0.050 |
| 4-40 | 0.050 |
| 5-40 | 1/16 |
| 6-32 | 1/16 |
| 8-32 | 5/64 |
| 10-32 | 3/32 |