Material

• Lock Nut: Alloy Steel.
• Finish: Phosphated and saturated with oil.
• Locking Pin: Sintered Steel.
• Grub Screw: Type MT6SS short pin, (DIN 915, 45H).

Performance

Thread Tolerance: 5H: ISO 965/3.
Recommended Tolerance for Mating Shaft Threads: 6g: ISO 965/3.
Dimension Standards: ISO 2982-2, except for the width Grub screw: ISO 4026, material class 45H.
Spanners: DIN 1810. (Available separately).

Other Info.

Lock nuts are used to locate bearings and other components onto a shaft or adapter sleeve.
They are also used for mounting bearings on tapered shaft seats and dismounting bearings from withdrawal sleeves.

Lock nuts have to be secured to prevent unintentional loosening.
This is done, either by a locking device that engages a keyway in the shaft or key slot in the adapter sleeve, or by a locking mechanism integrated in the nut.

Lock nuts with an integrated locking mechanism reduce the cost of the shaft as no keyway is required.

Installation is also quicker and easier because no separate locking device is necessary.
However, the loosening torque of these lock nuts requires more attention.

Lock nuts are locked on the shaft (sleeve) by friction.
The friction, and therefore the loosening torque, varies as a result of the accuracy of the tightening torque of the grub screw (locking screws), the surface finish of the shaft (sleeve) thread, the amount of lubricant on the thread, etc.
The lock nuts should be properly mounted and there should be only a limited amount of lubricant on the thread.

Sufficient locking for intended bearing applications.
Full locking effect is obtained when the nut is not pressed against the locked component.

KMK series lock nuts have a threaded steel insert in their bore to lock the nut in place on the shaft or adapter sleeve.
The threads on the insert match the locknut threads.
The insert acts as a pressure plate when a grub screw, which runs through the body of the lock nut, is tightened.

Lock nuts are intended to locate radial bearings in less demanding applications.

They should not be used on shafts with a keyway or on adapter sleeves with a key slot.

The locking device can be damaged if it aligns with a keyway or slot.

Installation and removal

There are slots around the circumference to accommodate a hook or impact spanner.

All lock nuts can be reused, provided they are not damaged. A new lock washer, locking clip or locking plate should be used each time the corresponding lock nut is installed.

A hex-key is needed to tighten the grub screws.
The screws should be tightened to the torque value listed in the product tables.