4-40X3/8 Phillips Pan Split Lock & Regular Flat Washer Sems Full Thread 18 8 Stainless Steel (Pack Qty 5,000) BC-0406SRPP188

A pan head machine screw with a free-spinning lock washer and flat washer manufactured as one assembly The washer/screw assembly makes this a locking screw with the helical washer providing the locking action and flat washer distributing the load over a wider area