NEMA 23 vs NEMA 17 and vs NEMA 34
The NEMA 23, NEMA 17, and NEMA 34 motors have a base dimension of 57x57mm, 42x42mm, and 86x86mm, respectively. The larger the base size of the stepper motor, the greater the static torque of the motor, the greater the torque when the motor is operating, and the greater the load the motor can support. These three types of stepper motors are frequently found on the market. In addition, there are NEMA6 (15mm×15mm), NEMA8 (20mm×20mm), NEMA10 (25mm×25mm), NEMA11 (28mm×28mm), NEMA14 (35mm×35mm), NEMA16 (39mm×39mm), NEMA17 (42mm×42mm), NEMA23 (57mm×57mm), NEMA24 (60mm×60mm), NEMA34 (86mm×86mm), NEMA42 (106mm×106mm) and other frame size stepper motors. NEMA 17 stepper motor NEMA stands for National Electrical Manufacturers Association, the largest association of electrical equipment manufacturers in the United States. As shown in the figure below, stepper motors with the same frame size have models with different lengths and different winding parameters. With the same frame size, the longer the stepper motor, the more windings that can be wound on the stator, and the greater the torque output. 
NEMA 17 stepper motor In addition to the difference in output torque, the axial load and radial load that the rotating shaft can bear are also different. 
NEMA 23 stepper motor refers to a stepper motor with an installation base size of 57mm×57mm, as shown in the following figure: 
NEMA 23 stepper motor 
NEMA 34 stepper motor refers to a stepper motor with an installation base size of 86mm×86mm, as shown in the figure below: 
NEMA 34 stepper motor 
NEMA 17 stepper motor In addition to the difference in output torque, the axial load and radial load that the rotating shaft can bear are also different. NEMA 23 stepper motor refers to a stepper motor with an installation base size of 57mm×57mm, as shown in the following figure: NEMA 23 stepper motor NEMA 34 stepper motor refers to a stepper motor with an installation base size of 86mm×86mm, as shown in the figure below: NEMA 34 stepper motor