Shear Strength

Verified by Rachel Mayfield, Supply Chain Analyst - April 2026

Shear Strength is the maximum stress a material can withstand in a direction parallel to its surface before failure, critical for bolt and pin calculations. When you're designing or maintaining mechanical assemblies, shear strength is key. For example, when selecting bolts for an application, you need to know how much lateral force they can handle without breaking. The same goes for pins used in hinges or pivot points. Shear stress comes into play whenever there's a sliding motion along a surface. Standards like ISO 6847 and BS EN ISO 6847 cover the testing methods for determining shear strength, while ISO 3269 and BS EN ISO 3269 detail material specifications. These standards provide guidelines on how to test materials under controlled conditions to ensure accurate results that engineers can rely on. For common materials like A2-70 stainless steel or SAE grade 8 carbon steel, shear strength values are well documented. A2-70 stainless has a typical shear yield strength around 590 MPa and ultimate tensile strength of about 630 MPa. For SAE grade 8, the shear strength is roughly 1240 MPa. Selecting components based on shear strength involves understanding both the material's properties and the stresses it will face in service. Engineers often use safety factors to account for uncertainties like manufacturing tolerances or environmental conditions. A common practice is to apply a safety factor of 3-5 times, ensuring that even under worst-case scenarios, the component won't fail due to shear stress. When choosing bolts or pins, consulting material data sheets and adhering to industry standards is important. Trade bodies such as CBM (Cranes and Hoists Manufacturers Association), BIAFD (British Industrial Fasteners Association) Ltd., BTMA (Bolt, Nut & Screw Association), and BPMA (British Portable Machine Tools Association) provide valuable resources and guidelines for selecting the right components based on shear strength requirements.