Spirol® Coiled Pins are designed with a unique 2-1/4 coil, allowing them to compress evenly and distribute stress equally. They compress from the outer edge inward, so force direction does not reduce flexibility or shear strength - as loads are applied from any direction, these pins compress into a solid tube. And since flexibility, strength, and diameter must be in proper relation to each other and to the hole, EFC offers the Flared version in Standard and Heavy Duties to suit your specific needs.