The location of maximum shear in the bolt is commonly referred to as a SHEAR PLANE. The bolt depicted in the above Figure is referred to as a “single shear bolt” since it has only one critical shear plane. It is possible to have more than one critical shear plane. The above Figure shows a bolt that has two critical shear planes. These bolts are said to be in “double shear” and can transfer twice as much force as a bolt in single shear. It is possible to have even more planes of shear.
The shear capacity of the bolt can be idealized as some material-based shear strength times the area of the failure surface (i.e. the cross-sectional area of the bolt).