Which component protects the surface from damage?

Which component protects the surface from damage?

• A. Clevis Bolt
• B. Eye Bolt
• C. Fillister
• D. Plain Washer

Answer: (D)

Protecting the surface comes from spreading the clamping force over a larger area. A plain washer sits between the bolt head (or nut) and the surface, providing a smooth bearing surface that distributes pressure so the material doesn’t crush, indent, or gall at the contact point. That load distribution is what prevents surface damage during tightening and under load, especially on softer materials. The other items aren’t meant for this protective role. A clevis bolt is used with a clevis for a pivoting connection, not to shield a surface. An eye bolt is an anchor point for lifting or rigging, again not for surface protection. A fillister head fastener is a screw with a raised head that concentrates pressure directly under the head rather than distributing it, so it doesn’t protect the surface in the same way a washer does.

Protecting the surface comes from spreading the clamping force over a larger area. A plain washer sits between the bolt head (or nut) and the surface, providing a smooth bearing surface that distributes pressure so the material doesn’t crush, indent, or gall at the contact point. That load distribution is what prevents surface damage during tightening and under load, especially on softer materials.

The other items aren’t meant for this protective role. A clevis bolt is used with a clevis for a pivoting connection, not to shield a surface. An eye bolt is an anchor point for lifting or rigging, again not for surface protection. A fillister head fastener is a screw with a raised head that concentrates pressure directly under the head rather than distributing it, so it doesn’t protect the surface in the same way a washer does.