Power Screw Design Calculator

Calculate torque to raise/lower loads and efficiency for power screws (Acme/square thread).

Axial distance the screw advances per revolution. For single-start, lead = pitch.
mm
Average of the major and minor diameters of the screw thread.
mm
The load to be raised or lowered by the power screw.
kN
Steel on bronze: 0.08-0.12. Steel on steel (dry): 0.15-0.25.
Friction at the thrust collar. Use 0 if a thrust bearing is used.

Results

Torque to Raise-Nm
Torque to Lower-Nm
Efficiency-%
Self-Locking-
Lead Angle-deg
References: Shigley's Mechanical Engineering Design, ASME/ANSI B1.5 Acme Thread Standard.