PMK Precision Locknuts — PSF Series are compact, high‑performance clamping nuts engineered to provide reliable axial locking and repeatable preload for bearings, spindles, and shaft assemblies. Designed for applications where space is limited but high axial capacity and precise positioning are required, PSF locknuts combine a slim profile with robust clamping geometry and multiple mounting options.

PSF nuts are available across a wide size and pitch range with standardized bolt patterns or through‑holes for secure installation. They are manufactured to tight tolerances, with machined faces and thread geometry that minimise runout and ensure consistent preload during repeated assembly cycles.

Key benefits

• Performance: supports axial loads from about 40 kN up to over 3,100 kN across the size range, making the series suitable for light to very heavy duty applications.
• Precision: fine thread pitches and ground seating faces ensure repeatable axial positioning and minimal bearing displacement.
• Range and compactness: available from small sizes (M12×1.0) up to large diameters (M300×4.0) while keeping a low axial height for confined installations.
• High clamping capacity: torque ratings specified per size (from ~4.5 Nm to 85 Nm) matched to axial load capability for safe, repeatable locking.
• Installation flexibility: multiple bolt patterns (through‑holes or threaded bolts), countersunk/clearance options and standard tool interfaces simplify integration.
• Durability: made from high‑strength steel with precision finishing; easily re‑used without loss of clamping performance when installed to recommended torque.

Applications

• Bearing and spindle locking in CNC machine tools.
• Ball‑screw end clamping and rotary table preload.
• Tool‑holding and fixture locking where compact, high‑capacity locking is required.
• Heavy‑duty presses, rolling equipment and industrial drives (larger PSF sizes).
• Retrofit and OEM assemblies that require repeatable axial setting with low runout.