Module: Introduction to timber engineering design Unit: Bolted and dowelled connection

Date Published

10 August 2022

Document Type




A dowel-type fastener refers to a nail, screw, bolt, plain dowel or threaded rod. A steel dowel typically has a tolerance on the diameter of -0/+0.1mm, inserted into a hole in the timber which has a diameter no greater than that of the dowel.

If necessary (e.g. in a steel-timber-steel joint) it may be threaded at each end to take nuts. The use of nuts and heads at the end of the steel “dowel” in bolts allows the bolt to bear onto the timbers and take axial loads if required. Hence, bolts and dowels could be explained similarly with the only difference being the inability of the dowels to resist axial loads.

Key Information

Bolted and dowelled connections were explained. Sizes and other limitations of both types of connectors were outlined, along with expressions to calculate the axial capacity of bolted connections.

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