Strength of Round Structural Pins

The design and performance of pinned connections has been investigated and reported in the literature extensively. Most of this work is concentrated on the connected plates, with relatively little attention given to the pins themselves. This paper summarizes past theoretical and experimental investigations of the performance of structural pins and uses that information to evaluate a practical design method that is consistent with a current lifting device design standard. The design of pins has customarily evaluated shear strength and bending strength independently. This is shown to be an acceptable practice as the maximum shear and the maximum moment normally do not occur at the same location. Comparison of the design loads based on the cited lifting device design standard to the failure loads of 13 pins of various material grades and dimensions shows a very high degree of scatter. The current practice of designing structural pins based on limit states of either first yield or a fully yielded section is reasonable and can be performed reliably, thus providing a pin design that is shown to be compliant with the design standard and capable of performing its necessary function. If design based on the failure load is required by a particular application, the proposed design must be investigated by destructive testing.