What is Shear (or shearing) Stress?
Shear is the stress caused by forces tending to slip or slide one part of a material in respect to another part. This is the stress that is placed on a piece of wood clamped in a vise and you chip away at it with a hammer and chisel. This type of stress is also exerted when two pieces of metal, bolted together, are pulled apart by sliding one over the other or when you sharpen a pencil with a knife. The rivets in an aircraft are intended to carry only shear. Bolts, as a rule, carry only shear but sometimes they carry both shear and tension.
