Self-Tapping Screws
Also known as sheet metal screws, self-tapping screws create their own threads as they are fastened into the material but typically requires a pre-drilled hole. Self-tapping screws have various thread types which are designed for different applications. Type A screws features a coarse thread with a pointed tip and is recommended to be used with resin-filled plywoods and thin sheet metals. Type B screws feature a fine thread with a blunt tip and is recommended to be used with plastics, thin sheet metals, and resin-filled plywoods. Type AB screws features the fine threading from the Type B and the pointed tip from the Type A and is generally recommended over Type A screws, particularly when used with brittle materials. High-Low screws, also known as HI-LO, features a double-lead thread and is recommended to be used with low density materials such as plastic and wood. The high-low threading reduces the driving torque, risk of thread stripping, and risk of cracking the mating material.
