The Carriage Bolt is a bolt with a round head, a flat bearing surface, and a square neck to prevent rotation.

The Carriage Bolt is manufactured under SAE J429 standards in grades 2 and 5, or ASTM A307 in grades A and B. Its finish can be Black oxide, Zinc-plated, or Galvanized.

Likewise, the Carriage Bolt is used in light-load wooden or metal structures.