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..
.Sheet metal screws make excellent fasteners for attaching metal hardware to wood because the fully threaded shank provides good retention in wood. 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.
USS flat washers have a large, wider body. SAE flat washers are machined to a tighter specification and have a smaller outside diameter. Flat Washer, Fits Bolt Size #8 ,Steel Black Oxide Finish, 25 PK.