The M4-0.7 x 20W9 JIS B1188 Phil Pan 304SS Split Washer 302/304SS Flat Washer Sems A2 Stainless is a type of fastener used to secure two or more pieces of material together. It consists of a split washer, a flat washer, and a screw. The split washer is placed under the screw head to help distribute the load and prevent the screw from loosening. The flat washer is placed over the screw head to provide a smooth surface for the screw to tighten against. The screw is then tightened to secure the two pieces of material together. This type of fastene