Fine-Thread Hex Nuts, Style 2 (ISO 8674) are specified where the joint requires a style 2 high hex nut on a fine-pitch thread for full-strength joints. The sections below cover the typical end-uses by industry, the size and material decisions for each, assembly practice, and the applications this fastener type is not suited to. Stocked across roughly M8 to M36, they cover general to heavy-duty work.
Typical Applications for Fine-Thread Hex Nuts, Style 2
The most common settings where these are specified:
- Automotive: fine-thread high-strength bolts.
- Machinery: fine-thread studs under high load.
- Pressure equipment: fine-thread flanges.
- Wind turbines: fine-thread assemblies.
How to Specify Fine-Thread Hex Nuts, Style 2 for Your Application
- Size: Match the nominal size to the mating thread or hole. This product spans M8–M36; check the full table below for the exact dimensions of each size.
- Locking & grade: Match the strength grade to the bolt, and choose a locking style (nyloc, all-metal, serrated flange) if the joint sees vibration.
- Environment: For damp, coastal or chemical exposure prefer A4/316 stainless or a suitable coating; indoors, plated steel or A2 is usually sufficient.
- Standard: This product is supplied to ISO 8674. Quoting the standard on your order guarantees interchangeable dimensions between suppliers.
Installation & Assembly Practice
- Run the nut down by hand before applying the wrench to catch cross-threading early.
- Tighten the nut rather than the bolt head where access allows — the torque-to-preload relation is more consistent.
- For locking styles, note that nyloc inserts are single-use in critical joints and lose grip above roughly 120 °C.
Common Selection Mistakes with Fine-Thread Hex Nuts, Style 2
- Pairing a high-class bolt with a lower-class nut — the nut strips before the bolt reaches proof load; the nut class must meet or exceed the bolt class.
- Using a plain nut with a spring washer in severe vibration instead of a prevailing-torque locking nut.
- Re-using nyloc nuts in critical joints.
Where Fine-Thread Hex Nuts, Style 2 Are Not the Right Choice
Not on their own — they need a matching bolt or stud — and a plain nut is not a substitute for a locking type under heavy vibration.
Custom manufacturing · Made to drawing
Need a fine-thread hex nuts, style 2 outside the standard range?
Height and across-flats are the two most often changed — a thinner nut for clearance, a larger hex for a tool that is already on the line. Made by cold heading or tapping.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
