What phase inductivity value should my stepper motor have?

Stepper motor phase inductivity varies widely. Even for a given size of stepper motor, such as NEMA17 with a length of 38mm, you can buy widely varying inductivity values even from the same manufacturer:

Both of these have the same holding torque of 80NcmInductivity is not an indicator of motor power!

As a general rule, remember:

  • NEMA17 steppers tend to be in the 1mH to 50mH range.
  • NEMA23 steppers tend to be in the 250μH to 25mH range

If you are checking your motor for a shorted winding, if the inductance is below 100μH, you can be pretty sure that the stepper motor is defective.