Diameter: 5/16"
Length: 4-1/2"
Head diameter: 0.703"
Nut diameter: 5/16"-18
Nut wrench size: 1/2"
Washer outside diameter: 7/8" Kit includes 50 Grade 307A carriage bolts, 50 USS thick washers, 50 Grade 2/A hex nuts Hot dip galvanized coating for superior corrosion resistance, Suitable for use in ACQ treaded lumber The flat head provides a semi-flush finish and is perfect for decks, gazebos, pergolas, and other heavy duty applications Meets or Exceeds: ASME B18.5, ASTM A307, ASME B18.2.2, ASTM A563, ASME B18.21.1, ASTM F2329