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Flexloc Lock Nut

Steel Class 8

Umbrako, Base DIN 980V

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Detail & Specs

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Class 8 Steel / FLEXLOC Coarse Thread
*Sold Per Piece*

"The Ultimate Lock Nut", FLEXLOC all-metal lock nuts spin freely until the thread of the mating fastener reach the slotted locking area at the top of the nut. The slotted section expands against the mating threads and locks the assembly together.

Recommended engagement: Tighten until mating screw is roughly 1.5 threads beyond the top locking portion of the nut.


  • Easy install and remove, Flexloc nuts can be reused (limited number of times)
  • High temperature applications to 425 degrees Celcius (no nylon insert)
  • Self Locking for Extreme vibration, shock and impact resistant
  • Does not need to be seated to lock / can be used as a "stop nut"
  • All threads of the nut carry the load equally for maximum strength

Class 8 metric lock nuts provide a medium strength, high tensile fastening solution. Commonly paired with Class 8.8 bolts and screws. Plated finishes provide corrosion resistance without sacrificing strength.

*Fully loadable when used with mating bolts: Class 8.8  /  Class 10.9  /  Class 12.9

Special Order Variations
Additional Sizes: M16, M20

Brand: Unbrako