Carriage bolt is a kind of hexagon bolt, specially used for carpentry, especially for fastening metal to wood. The carriage bolt is designed as a domed head to prevent loosening from one side, and an enlarged head shape also prevents the bolt from being pulled through the wooden structure.
The carriage bolt is a unique bolt with a mushroom head and a round shank cross-section. However, the part immediately below the mushroom head forms a square part. The head is usually shallow and dome-shaped. The square section has an ordinary threadless shank, and the diameter of the bolt shank is the same.