4-40 Square Machine Screw Nut Zinc (Pack Qty 5,000) BC-04NQ

Hex Machine Screw Nut: Designed to be used specifically with machine screws. Stainless nuts are used with stainless machine screws where parts are subject to corrosive conditions. Square Machine Screw Nut: Offers a greater bearing surface for wrenching Steel: Any low carbon steel. Stainless: 18-8 stainless steel