Description
5/16"-18 x 1" Chrome Grade 5 Carriage Head Bumper Bolts CBS5-145 (5 pcs.) Diameter: 5/16" Length: 1" Material: Steel Finish: Chrome Head Style: Carriage Thread Size: 18 (Coarse) Thread Length: Full Hardness: Grade 5 Style: Bumper Bolt Type: Carriage Bolt Box of 5. 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.