Torque Required to Overcome Friction between Screw and Nut while Lowering Load Calculator

Calculate Torque









Formula

The formula to calculate the Total Torque is:

\[ T = W_{\text{load}} \cdot \tan(\Phi - \psi) \cdot \frac{d}{2} \]

Definition

Total Torque is the measure of the force that can cause an object to rotate about an axis. Load is the weight of the body lifted by the screw jack. The Limiting Angle of Friction is defined as the angle which the resultant reaction (R) makes with the normal reaction (RN). Helix Angle is the angle between any helix and an axial line on its right, circular cylinder, or cone. Mean diameter of Screw is the distance from the outer thread on one side to the outer thread on the other side.

Example Calculation

Let's assume the following values:

Using the formula:

\[ T = 53 \cdot \tan(0.21816615649925 - 0.4363323129985) \cdot \frac{0.06}{2} = -0.352494513602206 \text{ Nm} \]

Conversion Chart

Load (W) Limiting Angle of Friction (Φ) Helix Angle (ψ) Mean Diameter of Screw (d) Total Torque (T)
50 N 0.21816615649925 rad 0.4363323129985 rad 0.06 m -0.332541993964 Nm
52 N 0.21816615649925 rad 0.4363323129985 rad 0.06 m -0.345843673723 Nm
54 N 0.21816615649925 rad 0.4363323129985 rad 0.06 m -0.359145353481 Nm
56 N 0.21816615649925 rad 0.4363323129985 rad 0.06 m -0.372447033240 Nm
58 N 0.21816615649925 rad 0.4363323129985 rad 0.06 m -0.385748712999 Nm
60 N 0.21816615649925 rad 0.4363323129985 rad 0.06 m -0.399050392757 Nm