The off-white nylon 6/6 shoulder washer, also called an insulator or shoulder spacer, offers a bearing surface and provides a protective barrier around a fastener to help minimize corrosion. Nylon 6/6 provides resistance to abrasion, corrosion, and many chemicals and solvents. The material is a strong yet lightweight plastic and is nonconductive. Nylon 6/6 can either absorb or lose moisture, which may alter its dimensions and mechanical properties.

Washers distribute the load of a fastener across a surface and can also be used as spacers, springs, shims, or locking devices. Several different washer styles fit a variety of application and installation requirements. The most common style is a flat washer. More specialized washers provide additional benefits. A cup washer, for example, helps protect fasteners from electrical currents, while a lock washer offers additional security in an assembled workpiece.