Glossary

Shear load is a sideways force applied across a material, fastener, or joint that tries to make one part slide past another. In a fastened assembly, shear load acts perpendicular to the fastener’s axis, rather than pulling along the length of the bolt or screw.

A simple example is a bolt passing through two overlapping plates. If one plate is pushed to the left and the other is pushed to the right, the bolt is loaded in shear. The force is trying to cut across the bolt’s shank at the joint line, almost like scissors trying to slice through the fastener.

Shear load is different from tensile load. Tensile load pulls a fastener lengthwise and tries to stretch it. Shear load pushes sideways across the fastener and tries to slide or cut it. In many real assemblies, a fastener may experience both tension and shear at the same time, but the terms describe different directions of force.

In fastener applications, shear load is important for bolts, pins, rivets, screws, anchors, dowel pins, clevis pins, and structural connectors. Parts exposed to sliding, side loading, vibration, impact, or bracket-style loading often need to be checked for shear. If the shear load is too high, the fastener may bend, deform, fracture, tear through the material, or cause the hole in the joined part to elongate.

Shear load can occur in single shear or double shear. In single shear, the fastener is being sheared across one plane, such as two plates joined together. In double shear, the fastener is supported in a way that creates two shear planes, such as a clevis joint with a center plate captured between two outer plates. Double shear usually allows the load to be shared across two sections of the fastener instead of one.

In simple terms, shear load is the sideways “slide-apart” force on a joint. It asks the fastener, “Can you keep these parts from moving past each other without being cut, bent, or broken?”