3-Piece Avbolt® Lockbolts are heavy duty structural blind fasteners which can be used on steel & aluminum. The 3-Piece design features a separate stem, collar and sleeve. This tamper resistant system is designed to create a permanent fixing for automotive, construction, container, railway, mining and bridge-building and security fencing applications. In addition, Avbolt® offers high tensile and shear strength in a blind lockbolt for single-sided and access-restricted installations.