HLB FAQ – Common Questions & Answers

Self-locking Performance FAQ

The Hardlock Bearing Nut provides a sufficient self-locking effect for any kind of adverse condition without the need to change the target application specifications.
Unlike a hexagon nut, a Hardlock Bearing Nut cannot be tightened with a strong force. The ability to manage the Hardlock Bearing Nut with an extremely low torque puts it into a league of its own.
No, there is no change in the self-locking effect if the concave nut is tightened first. Some customers tighten the concave nut first when there are few screw threads. In general, we recommend tightening the convex nut first if the target application is exposed to strong loads.
The Hardlock Bearing Nut can withstand more shock vibration than is needed to damage a tooth washer in the NAS vibration test.

• In places subject to heavy loads
• In places where there are repeated forward and reverse rotations
• In places with vibrations
• In places where maintenance is difficult after attachment
• In places where a high torque cannot be used for tightening

 

Product Selection FAQ

In addition to the standard and thin types, the Hardlock Bearing Nut is also manufactured to customer requirements. Check the dimension table to see if the Hardlock Bearing Nut is right for your target application.
The HLB is normally produced with an ISO tolerance class of 6H, but we also provide HLBs tailored to the tolerance class of the bolts/shafts for your target application.
The HLB is normally produced with ISO 6H tolerance zone class.
No. Although the HLB can be used with shaft having a keyway, it is not necessary, and a toothed washer is not required, either.
The three standard materials used for the HLB  are low-carbon, medium-carbon and stainless steel. If your target application has a temperature lower than -100° C (-148° F) or higher than 300° C (572° F), other materials and/or surface treatments should be considered. Contact us for a consultation.
Refer to the tightening torque table to find the value for the relevant nut size.
The upper and lower surfaces are finished but not polished.
 

Installation FAQ

Lubricant may be used if necessary, as it does not affect the self-locking effect. Lubricant is particularly helpful in HLB detachment.
No special tightening tool is required.
If you have tightened the convex nut to the bearing surface, then the convex nut does not need to be held in place while tightening the concave nut. However, if the convex nut is tightened at an intermediate position on the bolt/shaft, it should be held in place while tightening the concave nut to prevent both nuts from turning.
If the concave nut is tightened to our recommended torque, then the HLB will provide a sufficient self-locking effect even if there is a gap.
 

Maintenance after Installation FAQ

Apply lubricant to the bolt and the HLB. First remove the concave nut while holding the convex nut in place, and then remove the convex nut. Be aware that there is a risk of seizing if you attempt to remove the concave and convex nuts at the same time.
Whether an Hardlock Bearing Nut can be reused depends on environmental conditions, the HLB material and the target application. Before reusing the Hardlock Bearing Nut, manually install the concave nut onto the convex nut and make sure that there is a gap of one thread pitch. If there is not, please refrain from reusing. Contact us if you have any questions regarding reuse.
Yes, painting the HLB does not affect the self-locking effect.