Shank length and diameter: 1.1
River shank diameter is often determined by the joint’s required strength. But with sheet-metal components (on which most riveting is used), the diameter of the shank should be proportioned to the thicknesses of the workpieces.
Rivets with diameters that are too small can buckle. If the diameter is too large, the rivets are difficult to head. For most applications, it’s recommended that the diameter be 1.4 times the square root of t, where it is the thickest workpiece when t ≥1mm.