Provided Pack Washers are thin plates (typically disk-shaped) with an opening (typically in the in-between) that is usually employed to administer the load of a threaded fastener, such as nut or bolt. Other uses of these are as spring (Belleville washer, wave washer), wear pad, spacer, locking device, preload indicating device, and to cut down vibration (rubber washer). The products come with outer diameter (OD) about twice their inner diameter (ID) and differ quite widely. Pack Washers are commonly metal or plastic and stay in the demand of high-quality bolted concerts of hardened steel so as to preclude the loss of pre-load.