Squeeze these pins into holes and they expand slightly, creating tension to hold parts in place. They are often used as hinge pins and as fasteners for springs and power transmission components. An alternative to dowel pins, they're lighter in weight with a hollow center and don’t need a precise hole. Also known as roll pins.

Spring Steel—These pins won't deform from stress and vibration. Although they're stronger than stainless steel, they're best for dry environments since moisture will cause them to rust.

Zinc-Plated Spring Steel—These pins withstand occasional exposure to moisture. However, since friction from moving parts can wear away the finish, they're not ideal for wet environments. While not nearly as corrosion resistant as stainless steel, they are stronger and won’t deform under stress.

Black-Phosphate-Coated Spring Steel—The dark coating creates both a finished appearance and a barrier against rust that's more durable than clear zinc plating. Stronger than stainless steel, these pins won't deform from stress and vibration.