Hex nuts are to be used with machine bolts to adhere facing materials to prevent tension and shear movement. They are specifically useful in wood to wood, wood to metal or metal to metal applications. Hex nuts made with grade 2 zinc are recommended for most general uses. Parts are finished with a black ceramic coating that provides superior corrosion resistance. This black finish is designed to match the latest trends in hardware. When installing, be sure to pre-drill any holes and to use washers and bolts that are a similar grade and finish. These hex nuts measure 1/4 in. W. They feature 20 screw threads per in.USS coarse hex nuts are designed to be used with machine bolts to adhere facing materials while preventing tension and shear movementBlack ceramic coating combines the latest hardware trends with superior corrosion resistanceWhile installing, do not overtighten, overtightening risks stripping of threadsBe sure to use a nut that is consistent in thread size and finish with your other fastenersHex nuts are recommended for use with a 1/4 in.-20 bolt