A Phillips button-head SEMS screw is supplied pre-assembled as a button head machine screw with a retained flat washer and a retained spring lock washer. The fixed washers stay with the screw during handling; the rounded button head reduces contact points that could abrade cable insulation or exposed surfaces.

Materials offered include Grade 4.8 carbon steel and A2 (304) or A4 (316) stainless steel. Finishes listed are blue-white zinc, yellow zinc, black oxide, and passivated stainless. The flat washer distributes bearing load while the spring washer provides axial elasticity to help resist loosening. Typical uses include electrical cabinets, elevator components, sheet metal assemblies and decorative hardware. Please confirm required size, thread, material and finish when ordering.