O-ring Flat Washer Gaskets Flat washers protect surfaces by evenly distributing torque when a bolt or Flat Gasket is tightened. They prevent corrosion between a steel screw and an aluminum surface. Flat Ring Gasket can be placed under a machine screw to reduce noise and abrasion and offer electrical insulation. PTFE Flat Gasket is a thin plate (typically disk-shaped, but sometimes square) with a hole (typically in the middle) that is normally used to distribute the load of a threaded fastener, such as a bolt or nut. Other uses are as a spacer, spring (Belleville washer, wave washer), wear pad, preload indicating device, locking device, and to reduce vibration (rubber washer). Sample: Freely Business type: Manufacturer Delivery time:7~10 days