Ball Screw Mounting Torque & Pre-stretch

1. Why torque matters

The precision lock nut clamps the screw against the support bearing. Too loose → play and noise; too tight → bearing preload overload, heat and shortened life. Always follow the manufacturer's manual and tighten symmetrically, step-by-step.

2. Reference torque by lock-nut thread

General reference only — verify against the specific nut and bearing.

3. Pre-stretch for long strokes

Long screws grow with temperature during operation. Applying a small axial pre-stretch (per the manufacturer's coefficient) compensates thermal expansion and keeps the axis tensioned, reducing sag and drift. Pre-stretch must be balanced against the bearing's axial load limit.

4. Tightening procedure

1. Clean the shaft and nut seat; confirm the support face is flat.
2. Seat the bearing and the spacer; hand-start the lock nut.
3. Tighten in 2–3 steps to the reference torque, alternating sides for even clamping.
4. Re-check concentricity of the coupling and screw-to-rail parallelism (≤ 0.02 mm/m).

5. Related technical guides