Radiation Hardened Stepper Motor Frame Size Selection:

High energy, gamma radiation will attack all non-metallic materials in the motor. Lubricants, varnish, lamination bonding, and cable insulation deteriorate and ultimately crumble. Empire Magnetics' RH Radiation Hardened Stepper Motors combine the best available radiation resistant materials to provide motors with the longest possible service life in a radiation environment.
They have been tested to a total accumulated dose of 2 x 108 Rads. Frame size selection:

Radiation Hardened Stepper Motors are typically made in groups or families, the families are identified by the outer diameter or size of the square, these references are called frame sizes. In the American system, a 23 frame is a nominal 2.3 inches in diameter. For Radiation Hardened Stepper Motors less than one inch in diameter, the reference is typically known as a size. Herein is a list of the Radiation Hardened Stepper Motor frame sizes offered by Empire Magnetics Inc. and some of the characteristics of the group that will allow you to select from them.

Radiation Hardened Stepper Motor Frame Size 17: Nominal outer dimension of 1.7 inches, these motors are relatively low power useful for a wide range of industrial applications. Torque range of 13 to 26 oz-in. Cylindrical shaped Radiation Hardened Stepper Motor laminations, with square end flanges front and rear. Since this Radiation Hardened Stepper Motor does not have a housing, it is not available in all environments.

Radiation Hardened Stepper Motor Frame size 23: Nominal outer dimension of 2.3 inches. Extremely popular size useful for a wide range of industrial applications. Torque range of 60 to 150 oz-in. Cylindrical shaped Radiation Hardened Stepper Motor with square front flange.

Radiation Hardened Stepper Motor Frame size 34: Nominal outer dimension of 3.4 inches. Power range of 80- 240 watts, useful for a wide range of applications. Torque range of 150 to 450 oz-in. Cylindrical shaped Radiation Hardened Stepper Motor with square front flange.

Radiation Hardened Stepper Motor Frame size 42: Nominal outer dimension of 4.2 inches. Power range of 240-700 watts, relatively high power in the stepper motor range. Torque range of 400 to 1600 oz-in. Cylindrical shaped Radiation Hardened Stepper Motor with square front flange.