• Complete set of 512 pieces including hex bolts, nuts, flat washers, and lock washers • Composition: 95 hex bolts 1/4"-20, 60 bolts 5/16"-18, 42 bolts 3/8"-16, 105 hex nuts, 105 flat washers, and 105 lock washers • The bolts cover 15 frequently used sizes, with lengths from 13 to 52 mm • The nuts, lock washers, and flat washers have dimensions of 1/4-20, 5/16-18, and 3/8-16 inches • Made of grade 8 alloy steel, with a galvanized surface that provides resistance to corrosion, moisture, rust, and cold • Two types of washers: flat and lock, compatible with the included bolts and nuts, help distribute tightening load and prevent loosening • Ideal for small repairs, furniture installation, bridge construction, pipe valves, electrical equipment, industrial machinery, communication equipment, and building construction • All components are organized in a plastic box for easy storage and transport