Material: ZINC PLATED STEEL Assembled Product Length: 4" Grade: #2 Assembled Product Height: 0.25" Assembled Product Width: 0.25" Fastener Diameter (Imperial): 0.25" Fastener Length (Imperial): 4" Fastener Length (Metric): 101.6 MM Fastener Diameter (Metric): 6.35 MM . Domed top and a square under the head that pulls into the wood as the nut is tightened • Zinc plated • Nuts included • Grade 2