| Diameter - Thread Size | : | #8-18 |
| Drive Size | : | 1/4 in |
| Finish | : | Zinc Plated |
| Hardness | : | C52-58 |
| Head Type | : | Hex Unslotted |
| Material | : | Steel |
| Measurement System | : | Imperial |
| Point Size | : | #2 |
| Thread Length | : | 1/2 in |
Several common methods such as rivets, screws, and spot welding are used to fasten materials to ductwork. Three types of screws are most often used. The first is self-tapping only and requires a hole to be drilled before the screw can be utilized. The others are both self-tapping but also create their own holes. Self piercing screws have very sharp points which act much like a scratch awl in making a small opening in the steel for the threads to engage and work the sheet metal into a coned threaded hole. These work well for light gage steel. Self-drilling screws have an integral drill point which creates a large hole for tapping. This allows the screws to be used on heavy gages of steel. The maximum total thickness of steel that the self-drilling screw can be used with is determined by the drill point.
Duro Dyne® Super Saber® Self Drilling/Tapping Screw, Measurement System: Imperial, #8-18 Thread, Hex Unslotted Head, Steel, Zinc Plated, #2 Point, 1/4 in Drive, 1/2 in Thread Length, C52-58 Hardness
- Cold heading quality steel wire
- 0.166 to 0.161 in major dia
- 0.122 to 0.116 in minor dia
- Case hardened to rockwell C52-58