What formula is used to determine the diameter of a rivet?

The formula used to determine the diameter of a rivet in relation to the thickness of the materials being joined is based on ensuring sufficient grip and structural integrity. The correct approach is to use a factor that effectively accommodates the pullout strength and the shear strength of the material.

In practice, using three times the thickest sheet of material allows for a balanced engagement that provides enough strength while also ensuring that the rivet can be easily handled during installation. This factor is commonly accepted in aviation applications to ensure that the rivet can perform optimally under various loads without failing.

When considering the other options, using less than three times the thickness might compromise the rivet's performance, potentially leading to inadequate strength in the joint. Meanwhile, options requiring four or five times the thickness could lead to unnecessary weight and material usage, making the assembly less efficient without providing significant additional strength.