THK BNS-A Series Compact Type Precision Ball Screw/Spline

The THK BNS-A Series combines ball screw grooves and ball spline grooves crossing on a single shaft, with dedicated support bearings embedded directly into each nut’s circumference. This lets the shaft perform rotational, linear, and spiral motion just by rotating or stopping either nut, making it a popular choice for the Z axis of SCARA robots, assembly robots, and automatic loaders.

It has an 86mm outer diameter, weighs 1.67kg, and carries an inertia of 4.32 kg·cm². It carries a DN value of 70,000 and is available in screw shaft diameters from 8mm to 40mm, covering a solid middle ground between THK’s low-inertia BNS-V and heavy load BNS Series.