Hardlock Bearing Nut


The globally recognized HARDLOCK Bearing Nut (HLB)

The HARDLOCK Bearing Nut was developed with the same wedge design as HARDLOCK Nut and maintains an extremely effective self-locking effect. The HARDLOCK Bearing Nut’s high self-locking effect allows it to maintain a complete tightened state even during high-speed rotation, vibration, forward and reverse rotation and impact. We promise a significant cost down since it is maintenance-free.HLB-_img_all

■Very high self-locking effect

Just like the HARDLOCK Nut, no matter the conditions the self-locking effect remains secure.

■Enables Torque and Axial Force control

Can be completely locked in the middle of the shaft, adjustable positioning is also possible.

■Possible to re-use

All metal with little abrasion, sustains a high self-locking effect.

■Good and simple work ability

Easy installation with commercially available tools.

■Provides economic benefits

No other self-locking components such as washers etc., no key processing is required.
By switching to HLB the total cost is reduced significantly.


Self-locking design

Breakaway from complicated maintenance


By combining the Convex Nut designed with an eccentric conical protrusion (1) and the Concave Nut with its concentric conical depression (2), due to the wedge principle they will lock themselves onto the perpendicular axis of the shaft.


Due to the strong locking force created by the Wedge of the HARDLOCK Bearing Nut, no matter if it is exposed to severe impacts caused by high-speed rotation, the HARDLOCK Bearing Nut will stay intact!


The HARDLOCK Bearing Nut demonstrates a high self-locking effect no matter if the Concave Nut or Convex Nut is tightened first since it does not affect the perpendicular accuracy.

Stamp of quality assurance.



Impact vibration test conforming to NAS 3350/3354


The HARDLOCK Bearing Nut demonstrates excellent results on the Impact vibration test conforming to NAS 3350 standard test. Even under severe vibration and impact, the HARDLOCK Bearing Nut has proved to sustain a high self-locking effect as seen in the test results. As seen in the test results and data, the HARDLOCK Bearing Nut shows superior self-locking effect compared to other general-purpose nuts.

Junker Test


Forward and reverse rotation endurance test



Attachment Procedure


Install the Convex Nut manually by hand.


Use a tightening tool (Hook Spanner etc.) to tighten the Convex Nut to the appropriate torque required for the application.


Install the Concave Nut (Lock Nut) onto the Convex Nut manually by hand until it no longer turns. Prior to tightening of the Concave Nut, make sure that the space between the Convex Nut and Concave Nut is about 1 thread pitch.


Tighten the Concave Nut in the same way as the Convex nut. Use a torque wrench to tighten the Concave Nut to the recommended torque set by HARDLOCK Industry Co., Ltd.
*If a torque wrench is not available, tighten the nut by hand until it no longer turns, then use a regular tightening tool and tighten the nut more than one turn (360 degrees) for sufficient locking effect.


Even after tightening the nuts correctly, there is a chance that there is a gap between the nuts due to the tolerance of shafts diameter. However, even with or without a gap, if tightened correctly as instructed in this installation procedure, the HARDLOCK Bearing Nut will produce a sufficient locking effect.


If the bearing is fixed, the Convex Nut and Concave Nut can be installed in opposite order (Concave first, Convex second) with no reduction in the self-locking effect.