Also known as a coach bolt, the carriage bolt has a smooth, round domed head and a square neck directly under the head. The square shoulder seats into a drilled hole to prevent the bolt from turning while the nut is tightened. The domed head gives a rounded, low-profile finish on the exposed face.

Standards referenced include DIN 603, ASTM A307 / A325, ANSI/ASME B18.5 and GB/T 12. Typical applications are timber and wooden structures such as fences, beams and furniture assembly. When ordering, specify the required standard, diameter, length and finish to match the mating hardware and installation method.