A washer is a thin plate (typically disk-shaped) with a hole (typically in the middle) that is normally used to distribute the load of a threaded fastener, such as a screw 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). Washers usually have an outerdiameter (OD) about twice larger than their inner diameter (ID).
Washers are usually metal or plastic. High-quality bolted joints require hardened steel washers to prevent the loss of pre-load due to Brinellingafter the torque is applied.
Rubber or fiber gaskets used in taps (or faucets, or valves) to stop the flow of water are sometimes referred to colloquially as washers; but, while they may look similar, washers and gaskets are usually designed for different functions and made differently.
Washers are also important for preventing galvanic corrosion, particularly by insulating steel screws from aluminium surfaces.
The origin of the word is unknown; the first recorded use of the word was in 1346, however, the first time its definition was recorded was in 1611.
Washer Brass Washer Dowty Washer Spring Washer Body Galv Washer Flat Ss Washer Spring Galv Washer Brt Flat Washer Hdg Flat Washer Spring Ss Washer Black Cut Washer Hub Closed Washer Square Taper Washer Bonded Washer Hub Open Washer Square Z/P Washer Brt Flat Galv Washer Lock Ext Washer Thru Hardened Washer Copper Washer Lock Int Washer Cup Washer Nord-Lock