What is the WN1 specification?

The WN1 series (WN1-1 to WN1-8) includes different coatings and quality levels for fasteners, developed as an alternative to standard standards such as DIN EN ISO 4042 and DIN EN ISO 10683. The aim is to use REACH-compliant, high-performance and corrosion-resistant finishes suitable for such items as:

• high mechanical load;
• prolonged vibrations;
• temperature fluctuations;
• and exposure to aggressive environments.

Why is WN1 important?

For applications where every connection counts, such as in the defense sector or heavily loaded industrial systems, WN1 offers assurance in terms of:

• mechanical reliability (strength classes such as 8.8 and above);
• corrosion protection (e.g., ZnNi5 or ZnNi8 coatings);
• traceability and quality assurance through defined production and testing protocols;
• REACH compliance, excluding harmful substances such as CrVI.

Technical Characteristics

Depending on the application, different WN1 codes are applied, for example:

• WN1-1: ZnNi5 coating with coefficient of friction µ0.12-0.18, suitable for fasteners up to M80.
• WN1-2: ZnNi8 coating for heavier diameters (up to M300).
• WN1-4 & WN1-5: Zinc laminates, with high or standard corrosion resistance.
• WN1-6: Light Zn3 coating, especially for fine and small wire diameters.

Each specification is linked to a clearly coded designation (such as "ISO4762-M12x100-8.8-WN1-2") that makes it immediately obvious which standard and coating applies.

Applications in practice

Although originally developed for military applications, we are increasingly seeing WN1 specifications in other industries where safety, reliability and longevity of fasteners are critical:

• Aerospace
• Offshore and shipbuilding
• Rail infrastructure
• Power plants and nuclear facilities
• Heavy mechanical engineering

What does this mean for engineers and buyers?

When fasteners are selected for critical applications, using parts to the WN1 specification provides a demonstrable guarantee of quality. Suppliers working with WN1 codes thereby demonstrate that their parts meet the toughest requirements for mechanical performance, corrosion protection and traceability.

Want to know more about fasteners according to WN1?

Contact Archey for technical advice or access to our network of suppliers working with WN1-classified fasteners.