5/16-18 x 1 Serrated Hex Flanged Washer Full Thread Screw Case Hard Zinc 20NCUP188 which means that it will

which means that it will not loosen due to vibration or movement

while the deck screw design is optimized for use with decking materials

It has a slotted drive and a flat undercut head

These 12-24 x 1/2 Phillips Truss Full Contour Machine Screws are fully threaded and made of zinc-plated steel

5/16-18 x 1 Serrated Hex Flanged Washer Full Thread Screw Case Hard Zinc 20NCUP188 which means that it willThis 5 16 18 x 1 Serrated Hex Flanged Washer Full Thread Screw Case Hard Zinc is a high quality fastener designed for a variety of applications. The serrated hex flange washer head provides a secure grip and prevents the screw from loosening. The full thread design allows for maximum holding power. The case hardened zinc coating provides excellent corrosion resistance. This screw is perfect for use in automotive, construction, and other industrial