SFK Series

The SFK series is our heavy-load flagship product, combining smaller lead with increased ball circuits at the same shaft diameter. Compared to the SFU series, its dynamic load rating (Ca) is increased by 30%-50%, with significantly enhanced axial rigidity. This series is designed for complete assembly interchangeability with mainstream SFK series products, suitable for heavy-duty cutting machine tools, injection molding machine clamping mechanisms, high-thrust servo pressing, and other heavy-load, high-stiffness applications. Available in C5 and C7 accuracy grades.

Key Features

• Assembly Replacement – Direct replacement of existing same-series assemblies; custom shaft ends per customer drawings
• Ultra-High Load Rating – Multi-circuit (2-4 circuits) design; 30-50% higher dynamic load rating than same-diameter SFU
• Small-Lead Precision – Small lead on large shaft diameter (e.g., Ø32 with 4-5mm lead); high thrust & fine resolution
• Enhanced Rigidity – Enlarged nut OD and increased thread turns; stiffness superior to SFU and SFE
• Long-Life Design – Enhanced ball matching and heat treatment for continuous heavy loads & high impact

Replacing a ball screw? Model codes do not carry across brands, so see what to specify instead in our ball screw interchange guide.

Full Specifications