Module: Introduction to timber engineering design Unit: Multiple fastener joints
Joints in structural timberwork are commonly made with a variety of mechanical fasteners such as nails, screws, bolts or steel dowels. A number of fasteners arranged in one or more lines form a multiple fastener joint. The load-carrying capacity of such a joint depends on the strength of both the timber and the fasteners.
Standard tests on joint specimens involving a single fastener provide information on the embedding strength of the timber and tests on fasteners provide information on the bending strength of the fastener.
This unit explains how a multiple fastener joint is formed. The sum of capacities of individual fasteners may not be equal to the actual capacity exhibited by the multiple fastener joints, for a variety of reasons. Splitting of timbers in multiple fastener joints were considered, along with the effects of along-the-grain loads and perpendicular-to-grain loads. General recommendations to form multiple fastener joints were given.