STAINLESS STEEL FINE PITCH NYLON INSERT NUTS DIN 985

Fine Pitch Nylon Insert Nuts – FAQs

What is a fine pitch nylon insert nut?

A fine pitch nylon insert nut is a hexagonal nut manufactured with a metric fine thread and containing a nylon locking insert. The nylon insert deforms around the bolt thread during installation, creating resistance to rotation that helps prevent loosening under vibration.

These nuts are commonly referred to as fine thread nyloc nuts.

How do fine pitch nylon insert nuts work?

The nylon insert provides a prevailing torque by gripping the fine threads of the bolt. This increases resistance to loosening caused by vibration or movement, while the fine thread allows for greater thread engagement and more precise tightening compared to coarse thread equivalents.

When are fine pitch nylon insert nuts typically used?

Fine pitch nylon insert nuts are commonly used:

  • In applications subject to vibration or cyclic movement
  • Where fine adjustment or accurate preload is required
  • In mechanical and automotive assemblies using metric fine‑threaded bolts
  • Where a self‑locking nut is required without additional locking devices

They must always be matched with the correct metric fine‑threaded fastener.

Are fine pitch nylon insert nuts suitable as a primary fastening nut?

Yes. Fine pitch nylon insert nuts are suitable for use as primary fastening nuts, provided they are correctly selected for the application. The nut body carries the mechanical load, while the nylon insert provides resistance to loosening.

Can fine pitch nylon insert nuts be reused?

Fine pitch nylon insert nuts may be reused, provided the nylon insert still offers sufficient resistance to rotation. Repeated use will reduce the effectiveness of the nylon insert, and the nut should be replaced if the prevailing torque is noticeably reduced.

Are fine pitch nylon insert nuts suitable for high‑temperature applications?

No. Due to the presence of the nylon insert, fine pitch nylon insert nuts are not suitable for high‑temperature applications where the nylon could soften or degrade. Alternative locking methods should be used where elevated temperatures are expected.

What thread types and sizes do you supply?

We supply metric fine pitch nylon insert nuts only.
These nuts are not interchangeable with coarse thread fasteners and must be matched precisely to the correct fine thread bolt or stud.

What materials are available?

Our range of fine pitch nylon insert nuts is available in:

  • Stainless steel A2
  • Stainless steel A4

Are fine pitch nylon insert nuts known by any other names?

Fine pitch nylon insert nuts may also be referred to as:

  • Fine thread nyloc nuts
  • Fine pitch nylon lock nuts
  • Fine thread nylon insert nuts

All describe the same nut design combining a fine thread with a nylon locking insert.

How do I choose the correct fine pitch nylon insert nut?

When selecting a fine pitch nylon insert nut, consider:

  • Correct metric fine thread size and pitch to match the mating bolt
  • Application temperature, ensuring it is suitable for a nylon insert
  • Vibration levels and service conditions
  • Material selection (A2 or A4) based on corrosion resistance requirements