Self Drilling screws can be identified by the drill bit-shaped point of the screw and are designed for various applications, such as fastening metal to metal.
The variety of heads are
| Dia | Length | Drill Drive Size |
|---|---|---|
| 3.5 (#6) | 13mm to 50mm | #3 |
| 3.9 (#7) | 25mm & 50 mm | #3 |
| 4.2 (#8) | 32mm to 75 mm | #3 |
| 3.9 (#7) | 32mm to 75mm | #3 |