1 1/4-7 x 5 1/2 Coarse Thread Socket Head Cap Screw Black DFAR MPT188 The screw is made from

The screw is made from steel and has a zinc coating for added durability

This 1/2" internal tooth lock washer is made of zinc-plated steel for superior corrosion resistance and durability

full thread for increased holding strength

5/16-18 x 6 Six Lobe Flat Floor Board Screw Type F Black Phosphate

1 1/4-7 x 5 1/2 Coarse Thread Socket Head Cap Screw Black DFAR MPT188 The screw is made from1 1 4 7 x 5 1 2 Coarse Thread Socket Head Cap Screw Black DFAR is a high strength fastener designed for use in demanding applications. It is made of alloy steel and features a black oxide finish for corrosion resistance. The coarse thread design provides a secure hold in a variety of materials. The socket head allows for easy installation and removal using a hex key. This screw meets the requirements of the Defense Federal Acquisition Regulation