Commonly used with flat or lockwashers.
Especially useful in metal-to-metal or where heavy duty fastening is required..#4-40 x 5/8 in Phillips Flat Machine Screw, Zinc Plated Steel, 60 PK Machine screws are used in fastening nearly all types of hard materials. A machine screw, also called a stove bolt, is generally a smaller fastener threaded the entire length of its shank.