Which fastener component should always be used to prevent stress concentrations from burrs and sharp edges from manufacturing?

Which fastener component should always be used to prevent stress concentrations from burrs and sharp edges from manufacturing?

• A. Washers
• B. Nuts
• C. Flange
• D. Caps

Answer: (A)

When a bolt is tightened, burrs and sharp edges around the hole act as stress raisers, concentrating force at a small area and increasing the risk of cracking or tearing. A washer provides a smooth, larger bearing surface between the fastener and the workpiece, spreading the clamping load over a wider area. This reduces localized peak stress near the burr or edge and protects the material from deformation or crack initiation during tightening and service. Nuts secure the bolt but don’t change how the load is distributed on the surface. A flange offers a built-in bearing surface on the fastener, but it doesn’t specifically address contact with rough edges or burrs. Caps are protective or cosmetic and do not improve load distribution. Therefore, the washer is the appropriate choice for mitigating stress concentrations from burrs and sharp edges.

When a bolt is tightened, burrs and sharp edges around the hole act as stress raisers, concentrating force at a small area and increasing the risk of cracking or tearing. A washer provides a smooth, larger bearing surface between the fastener and the workpiece, spreading the clamping load over a wider area. This reduces localized peak stress near the burr or edge and protects the material from deformation or crack initiation during tightening and service.

Nuts secure the bolt but don’t change how the load is distributed on the surface. A flange offers a built-in bearing surface on the fastener, but it doesn’t specifically address contact with rough edges or burrs. Caps are protective or cosmetic and do not improve load distribution. Therefore, the washer is the appropriate choice for mitigating stress concentrations from burrs and sharp edges.