THK BSM Series Full-Ball Type Precision Ball Screw (High-Speed, Machine Tools)

The THK BSM Series is a full-ball ball screw built specifically for modern machine tools, offering high load ratings alongside fast feed rates. THK developed a new ball circulation system for this series, pushing the DN value up from 130,000 in conventional products to 170,000, and paired it with large leads to reach feed speeds of up to 121 m/min. A revised groove profile on both the screw shaft and nut also raises the load rating compared to older full-ball designs.

The nut is slimmer and longer than THK’s earlier models, giving surrounding parts a more compact design while adding rigidity through more integrated ball circuits. It’s available in screw shaft diameters from 40mm to 63mm, with a slim nut BSM-B variant also available in diameters from 36mm to 50mm for tighter installations.