The transition between the shank and head of most fasteners has a slight radius known as what?

The slight radius that exists at the transition between the shank and head of most fasteners is known as a fillet. This rounded design serves several purposes in the engineering and manufacturing of fasteners. It helps to reduce stress concentrations that can occur at sharp corners, which is critical in maintaining the structural integrity of the fastener when subjected to loads. By having a smooth transition rather than a sharp edge, the fillet also facilitates better fit and alignment during assembly, enhancing overall performance and durability.

Understanding the significance of the fillet can aid in choosing the right fastener for applications requiring reliable load-bearing capabilities while minimizing risk of failure due to stress points.