The HARDLOCK Nut resists loosening from vibration longer than most other available fasteners or locking nuts.

Supplied by Staytite, this is because the HARDLOCK Nut uses a unique wedge principle to create an unprecedented and powerful self-locking force. It has become a top choice for engineers in the UK, America, Europe, and Japan.

How does it work?
The HARDLOCK solution is to use two nuts to play the roles of the hammer and wedge, respectively. A small eccentricity in the sliding part of the convex top of the lower nut acts as the wedge. When the concave upper nut is tightened, the effect produced is exactly the same as that produced by a hammer driving in a wedge.

Moreover, it’s much more effective to use a screw as this makes it easy to force the wedge into place.

Repeated usage does not reduce the locking ability of Hardlock Nuts. Neither will there be undue wear on either of the nuts or on the thread of the bolt as a result of frequent removals and subsequent re-installation.

Each HARDLOCK Nut passes the American vibration and impact test to the NAS 3350 & NAS 3354 (National Aerospace Standard) by a huge margin. This testing certifies that each of these fasteners provides a remarkable locking force, being able to resist any impact and remain in a stable locked condition.

The high anti-loosening effect satisfies most requirements, including easy installation, re-useability (several dozen times), and reduced lifetime costs because of less maintenance and inspection.

Learn more about the HARDLOCK solutions in this brochure.