Also known as roll, tension, split, and expansion pins, these pins have a slot along one side that you squeeze closed to install them into unthreaded holes. Once installed, they expand slightly, creating outward tension that holds them tight against the hole wall. These pins absorb shock and vibration in your system, and keep parts from loosening. They are often used as hinge pins, or to hold springs and power transmission components in place.

Install these pins into a hole slightly smaller than the pin diameter. They have at least one chamfered end, which means the end is angled to make insertion easier.

Breaking strength is measured as double shear, which is the amount of force required to break a pin into three pieces.

Some metric pins with the same diameter come in two different wall thicknesses. Thinner walls are more flexible, easier to install, and won’t weigh down your assembly as much as thicker pins. Layer a pin with a thin wall inside a pin with a thicker wall to increase the breaking strength. Make sure the slots are opposite one another for maximum strength.

Steel pins are strong and wear resistant. Pins with a black-phosphate or zinc-plated finish have an outer layer to protect the steel underneath from rust.

18-8 stainless steel pins offer a balance of strength and corrosion resistance.

400 series stainless steel pins resist wear from abrasion and have some corrosion resistance.

420 stainless steel pins are as strong and wear resistant as steel, with the addition of corrosion resistance in wet environments.

Passivated pins offer added protection against corrosion and oxidation.

Pins that meet ASME B18.8.2 specifications are made to ASME standards for material and dimensions.

Pins that meet MS16562 conform to military standards for material and dimensions.

Pins that meet specifications for ISO 8752 (formerly DIN 1481) or ISO 13337 (formerly DIN 7346) adhere to international standards for pin dimensions.