Washers are typically disk-shaped spacers with a hole for a screw or bolt to thread through. They are used to distribute the load of a head or nut to prevent penetration into surface material. Many washers incorporate mechanisms to resist the threaded device being undone including spring, spring-lock, toothed and Belleville-style washers. These washers are used to prevent vibration and stress changes loosening the nut or screw. Rubber and silicon washers are used for vibration reduction. Washers are also used for insulating gaskets, sealing bolt holes and as plumbing seals in taps. Washers can also be used to create galvanic isolation between dissimilar materials to prevent electrolysis/corrosion.Washers are typically specified in standard through-hole sizes, inner and outer diameter. Washers of different thicknesses and materials – including plating materials are available in many different shapes. A common shape variant is a circular washer with inner teeth that provide thread contact and hold the washer firmly on the screw or bolt preventing it from falling off while being installed. Retaining washers have a thin inner diameter (that could be inner teeth) that threads and holds the bolt. Sealing washers are typically a cup like shape or have circular serrations that provide for sealing when under a torque. 더 읽기 읽기 안 함