I'm concerned about the heat (surface temperature) of stepping motors (including αSTEP). Is this abnormal?

It can be used if the motor case surface temperature is 100°C or less.

The motor's insulation class is Class B insulation, with an allowable temperature of 130°C for the windings. Since there is an expected temperature difference of 30°C between the inside of the motor and the case surface, the upper limit on the case surface is 100°C.


Use the AZ series at a motor case surface temperature of 80°C or less. If the ABZO sensor temperature reaches 85°C or higher, a motor overheat protection alarm will occur.

Consider the lifespan of the motor's ball bearings, attach them to a metal plate with good thermal conductivity, and use them at the lowest possible temperature. The bearings have a lifespan of 50,000 hours when the motor case surface temperature is 80°C. If used at temperatures above 80°C, the motor's lifespan will be shortened.


The UL/CSA certification requirement is Class A insulation (105°C). When applying for a set as a UL/CSA certified product, please use the motor at a surface temperature of 75°C or less.


If you are concerned about the surface temperature of your stepping motor, there are ways to prevent the temperature from increasing.