Retainers include products, which, although they cannot initially stop self-unscrewing, prevent complete unscrewing after a more or less large pretension loss. This will stop the connection from falling apart.

This category includes nuts with

  • Polyamide inner rings (lock nuts with a plastic ring)
  • All-metal lock nuts
  • Thread inserts and screws with a clamping piece according to DIN 267, part 28

Retainers also include thread-rolling screws

  • Retainer due to the special thread
  • Self-tapping screws form their mating thread themselves
  • The positive locking between the bolt thread and the nut thread ensures a tight fit
  • Fibre alignments are not interrupted but rather reshaped and strain-hardened