FAQs

Anti-loosening/lock nuts

• What does the anti-loosening customisation actually change?

  It replaces the standard F1/SF1 nut with a prevailing–torque lock nut, which incorporates a stainless steel locking element that resists rotation under vibration.

• Which thread sizes can be specified with anti-loosening customisation?

  M6, M8, M10, and M12 only. M4 and M5 are unavailable through this route due to our product manufacturing limitations. Contact us to ask about alternative options for M4 or M5 thread sizes.

• Why is installation torque higher than with standard nuts?

  Prevailing–torque lock nuts introduce additional friction via a mechanical locking feature, increasing the running torque required during assembly.

• Will I need a different screw length for a fastener with a lock nut?

  Possibly. The lock nut design has different height and thread engagement lengths, so you may need a slightly longer screw to ensure proper engagement with the locking feature.

• Will the mechanical performance change compared to standard bigHead F1/SF1 products?

  Yes. The lock nut design uses different geometry, and the associated WLL and tightening torque values are not the same as standard products. We can supply the correct values for your specification on request.