Prevailing Torque Six-Lock, Flex Locknut

The DURA-FLEX all-metal prevailing-torque locknut features a slotted collar, which creates six flex-locking elements along its top. When installed, these elements provide a solid locking mechanism.

DURA-Flex locknuts are available in sizes up to 3” in diameter, with special-light or heavy-torque-installed versions. These locknuts can be ordered in American Standard and Metric: hex finished, jam, heavy thin, heavy full, finished, jam, hi, and specials.


Steel grade 2-5-8, 2H/DH, Monel, brass, bronze, stainless steel, and a selection of exotic metals


UNC, UNF or 8UN Series, Class 2B, 3B, left-hand thread, and Metric


Plain, zinc, and cadmium, as well as other platings and coatings