A flat washer is a thin, usually round, plate with a hole in the middle that is normally used to distribute the load of a threaded fastener. USS flat washers have a large, wider body. SAE flat washers are machined to a tighter specification and have a smaller outside diameter. As the industrys most trusted fastener supplier, Midwest Fastener has earned a reputation for delivering a complete line of high-quality bulk and construction fasteners to meet consumer needs. Contractors and DIYers alike have come to depend on Midwest Fastener to provide them with the critical parts and fasteners necessary to ensure the success of their projects.