Beyond the 30° Flank
HKF locks at NIKKI's unique flank angle rather than the conventional 30° contact, keeping the difference between locking torque and surface pressure within 10%. That uniformity prevents loosening, overheating, and noise on high-speed assemblies.
The full explanation is on the Ultra-Uniform Locking Series page.
No Thrust Washer or Keyway
Fewer parts, simpler assembly
Reusable If Handled Properly
Assemble and disassemble repeatedly
Ground Contact Surface and Thread
High-precision grinding process
3 or 6 Set Screws Per Nut
M5 to M12, 4.8 to 60 Nm max
Where HKF Locknuts Are Used
Machine Tool Spindle Bearing Retention
Ball-Screw Support Bearings
Rotary Tables & Index Heads
High-Vibration Assemblies
HKF Specifications
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Products in this Ultra-Uniform Locking Series
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Questions About the HKF Locknut
The HKF is the standard-height locknut in NIKKI's Ultra-Uniform Locking Series, in metric threads from M15 x 1 to M200 x 3 with 0.002 mm maximum axial run-out. The questions below are the ones buyers ask before a first order.
Contact UsThe maximum axial run-out is 0.002 mm. Both the thread and the contact surface are finished by high-precision grinding, which is what holds the run-out to this level.
Often, since HKF covers standard metric fine threads from M15 x 1 to M200 x 3, and its flank locking needs no keyway or tab washer. Confirm the outside diameter and height against the dimension table, as the envelope differs from KM dimensions.
Each size lists a catalog maximum per screw in the dimension table, from 4.8 Nm for M5 set screws up to 60 Nm for M12. Tighten gradually and alternately rather than one screw fully first.
Add L to the order code for a left-hand thread (HKF30x1.5P-L) or U for an inch thread (HKF30-U18). Standard right-hand metric versions are ordered by the plain name.
HKR suits assemblies where axial space is limited. It's the low-profile version of the same series, with body heights from 8 mm against HKF's 14 mm, using smaller set screws at the small end of the range.
No. The unique flank angle locking works directly between the set screws and the thread flank, so neither a thrust washer nor a shaft keyway is required, and the nut is reusable if handled properly.