A self-drilling screw, or tek screw, is similar to a sheet metal screw, but it has a drill-shaped point to cut through the substrate to eliminate the need for drilling a pilot hole..Ideal for any project involving light gauge sheet metal, awnings, door and window frames, gutters, sheds.
Often used for mounting legs on tables.. A hanger bolt is a headless fastener that has machine screw threads on one end and self-tapping threads on the other designed to be driven into wood or another soft substrate.