Mechanical and liquid-applied threadlocking add-ons consist of fully adjustable nylon locking pellets and strips attached to the thread surface of high-pressure self-sealing screws, bolts, and nuts to maximize antivibration dampening. The devices remain locked whether the fastener is seated or unseated. are impervious to chemicals, water, and motor fluids and will not dry, shrink or lose resiliency when exposed to solvents, alcohol, gasoline, or caustic soda. Depending on the locking material, the devices are reusable to 550°F. Also available is a ready-to-install patch dry-coating process fused to selected threads.

APM Hexseal Corp., 44 Honeck St., Englewood, NJ 07631, (800) 498-9034,