A machine screw, also called a stove bolt, is generally a smaller fastener threaded the entire length of its shank. Commonly used with flat or lockwashers. Especially useful in metal-to-metal or where heavy duty fastening is required..
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.