ASME B18-12 pdf download GLOSSARY OF TERMS FOR MECHANICAL FASTENERS These fasteners usually have a tensile strength in excess of 120,000 psi. 2.1.7 lockpins and collars: a headed and externally grooved mechanical device designed for insertion through holes in assembled parts. A cylindrical collar is swaged into the external groove as the lock pin is hydraulically tensioned. Collars are either...