How to Calculate Holding Torque

A stepper motor is a good demonstration of holding torque.
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When designing motors used to power rotational devices engineers need to understand the engine’s sensitivity to force. This phenomenon is generally recognized as torque. According to Intelligent Motor Systems (IMS) holding torque is the maximum force that can be externally applied to a stopped, energized motor without causing the rotor to rotate continuously. This concept is demonstrated in a stepper motor which is used to convert digital pulses into mechanical shaft rotations.

    Determine the components. Holding torque is derived from torque sensitivity and maximum current, where torque sensitivity is measured in Newton-meters per amp (Nm/Amp) and maximum current is amps.

    Identify the formula. Holding torque is computed as torque sensitivity x maximum current.

    Calculate holding torque. Where torque sensitivity is 4.675 Nn/Amp x 10 raised to the power of (-3) and maximum current is 0.35 amps, holding torque is 4.76 x 10 power (-3) x 0.35 which equals 7.93 x 10 power (-3) Nm.