18-8 Stainless Steel split lock washers are used under bolt heads or nuts to increase the hold of the fastener or to increase the bearing surface. Split lock washers are helical-shaped split rings. When fastened, the two ends exert a spring force on the fastener to create increased friction and resistance to motion. Dimensional specifications are governed by ASME B18.21.1. 18-8 stainless steel fasteners are commonly used in applications that require general atmospheric corrosion resistance, such as chemical and food processing equipment.