In solid mechanics, shearing forces are unaligned forces acting on one part of a body in a specific direction, and another part of the body in the opposite direction.
"[1] This section calculates the force required to cut a piece of material with a shearing action.
In this case 0.6 applies to the example steel, known as EN8 bright, although it can vary from 0.58 to 0.62 depending on application.
To calculate the force to shear a 25 mm diameter bar of EN8 bright steel; When working with a riveted or tensioned bolted joint, the strength comes from friction between the materials bolted together.
The shear force only becomes relevant when the bolts are not torqued.