5/16 -18 x 6 Galvanized Grade 2 / A307 Carriage Bolts CBS-427 (50 pcs.)

Diameter: 5/16 Length: 6 Material: Steel Finish: Hot Dip Galvanized Head Style: Carriage Thread Size: 18 (Coarse) Thread Length: Full Hardness: Grade 2 / A307 Type: Carriage Bolt Square-Depth: 3/16 Box of 50. A carriage bolt has a domed or countersunk head and the shank is topped by a short square section under the head. The square section grips into the part being fixed (typically wood) preventing the bolt from turning when the nut is tightened.