Carriage Bolts: Wednesday's Word(s) Of The Week

Carriage bolts are a special type of bolt used in wood construction. Instead of a hex-head, they have a rounded, dome head. These bolts are used where people or objects might rub against the bolt head, such as a floor surface or railing. The head bears smoothly on the wood surface, without need for a washer.

The rounded head can't be gripped by a wrench, so a special feature of carriage bolts is a square profile just under the head. As the bolt is seated, this grips the wood and prevents the bolt from spinning as the nut is tightened.

*Wednesday's Word Of The Week is a feature on Unalam's Wood Times Blog. Each Wednesday our structural engineer, Rik Vandermeulen, will discuss a new term associated with glulam manufacturing. He will do this until we run out of words. If there is a timber or glulam term that you have heard of and want to know more about, let us know in the comments.