4-40 K Lock Nut 18-8 Stainless Steel Nut, 420 Stainless Steel Washer (Pack Qty 2,000) BC-04NK188

K Lock Nut 18-8 Stainless Steel Nut, 420 Stainless Steel Washer

This is the most popular type of locknut because of its versatility, cost and ease of installation. Doesn't gall screw threads