Diameter: 5/16Length: 1-1/2Material: SteelFinish: ZincHead Style: Hex Washer (Hex)Point Type: Type FThread Size: 18 (Coarse)Thread Length: FullType: Sheet Metal ScrewBox of 8.A sheet metal screw has sharp threads that cut into a material such as sheet metal, plastic, wood, hard rubber, aluminum, and other comparable compositions. Sheet metal screws make excellent fasteners for attaching metal hardware to wood because the fully threaded shank provides good retention in wood.