How to Choose a NEMA 17 or NEMA 23 Stepper Motor
Choose a NEMA 17 motor for 3D printer axes and light CNC work. Choose a NEMA 23 motor for CNC routers and mills that need more holding torque. NEMA 17 motors hold 0.22 to 0.36 Nm at 1.2 to 1.3A. NEMA 23 motors hold 1.9 to 3.0 Nm at 2.8 to 4.2A. All four use a 1.8 degree step angle.
Quick facts
| Fact | Value |
|---|---|
| NEMA 17 frame | 42 mm square |
| NEMA 23 frame | 57 mm square |
| Step angle | 1.8 degrees, 200 steps per revolution |
| NEMA 17 torque | 0.22 to 0.36 Nm |
| NEMA 23 torque | 1.9 to 3.0 Nm |
| Shafts | 5 mm on NEMA 17, 8 mm on NEMA 23 |
What do NEMA 17 and NEMA 23 mean?
The NEMA number names the motor frame size: NEMA 17 motors measure 42 mm square, and NEMA 23 motors measure 57 mm square.
All four motors here use a 1.8 degree step angle, which gives 200 steps per revolution.
The listings state 5% step accuracy for the 4-pack and for the 1.9Nm NEMA 23 motor.
Which NEMA 17 motor fits?
The single NEMA 17 motor holds 0.36 Nm at 1.2A per phase, with a 20T MXL gear installed on its 5 mm shaft.
The gear suits belt drives without extra parts, with 7.5 inch leads, 3 mm mounting holes, and 12V recommended.
The 4-pack holds 0.22 Nm each at 1.3A per phase, with a suggested input of 12 to 24V and a weight of 220 g each.
Which NEMA 23 motor fits?
The 76 mm NEMA 23 motor holds 1.9 Nm at 2.8A per phase, with an 8 mm shaft and a 57 by 76 frame.
The 100 mm NEMA 23 motor holds 3.0 Nm at 4.2A per phase. It has an 8 mm shaft and a recommended voltage of 24 to 48V.
The longer body holds more torque than the 76 mm motor, for CNC axes and builds that need extra holding power.
Which driver and bracket pair with each motor?
The DM542 driver suits NEMA 17 and NEMA 23 motors, with DC 20 to 50V input and 1.0 to 4.2A peak current.
The DM860H driver suits NEMA 34 motors and other large steppers, with output current up to 7.2A and a cooling fan.
The steel bracket fits NEMA 34 motors, with 6 mm thick steel. It includes 4 M5 screws and 4 M5 nuts, and the motor is not included.
What did we check on the bench?
We checked each listing states its holding torque, rated current, step angle, shaft size, and frame size.
We counted 2 images on the single NEMA 17 listing and 3 on the 4-pack listing. We counted 3 on the 1.9Nm listing and 4 on the 3.0Nm listing.
We matched every price here to the live store price on November 12, 2026.
How the options compare
| Motor | Torque | Current | Frame | Shaft | Price |
|---|---|---|---|---|---|
| NEMA 17 single | 0.36 Nm (50 oz.in) | 1.2A | 42 mm | 5 mm | $9.99 |
| NEMA 17 4-pack | 0.22 Nm (30.5 oz.in) | 1.3A | 42 mm | 5 mm | $27.99 |
| NEMA 23 | 1.9 Nm (269 oz.in) | 2.8A | 57 mm | 8 mm | $34.99 |
| NEMA 23 long | 3.0 Nm (425 oz.in) | 4.2A | 57 mm | 8 mm | $44.99 |
How do you size a motor for an axis?
- Measure the mounting frame and shaft size the axis needs, 42 mm or 57 mm square.
- Pick the holding torque the axis needs, from 0.22 Nm up to 3.0 Nm across these motors.
- Check the rated current per phase, and pick a driver whose current range covers it.
- Check the shaft size and the gear or pulley fit, including the 20T MXL gear on the single NEMA 17.
- Mount the motor, wire the driver, and run the axis slowly before full-speed moves.
Parts that fit this guide
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Nema 17 Stepper Motor, 0.36Nm, 1.2A, with 20T MXL Gear ($9.99)
Nema 17 stepper motor at $9.99. 0.36Nm holding torque, 1.2A per phase, 20T MXL gear installed, 5 mm shaft, 12V recommended.
Nema 17 Stepper Motor, 0.22Nm, 1.3A, 4-Pack ($27.99)
Nema 17 stepper motor 4-pack at $27.99. 0.22Nm each, 1.3A per phase, 12 to 24V suggested input, 220 g each.
NEMA 23 Motor, 1.9Nm, 2.8A, 8mm Shaft ($34.99)
NEMA 23 motor at $34.99. 1.9Nm holding torque, 2.8A per phase, 8 mm shaft, 57 by 76 frame.
NEMA 23 Motor, 3.0Nm, 4.2A, 8mm Shaft ($44.99)
NEMA 23 motor at $44.99. 3.0Nm holding torque, 4.2A per phase, 8 mm shaft, 57 by 100 frame, 24 to 48V recommended.
Related parts: DM542 Stepper Motor Driver for 42/57 Series: DM542 stepper motor driver for 42 and 57 series motors; DM860H 2-Phase Stepper Motor Driver with Cooling Fan: DM860H 2-phase stepper motor driver with cooling fan, for large motors; Steel Mounting Bracket for NEMA 34 Motors: Steel mounting bracket for NEMA 34 motors, motor not included.
Shop the full range: Stepper Motors & Drivers at Quality RC Parts. See also: Related guide.
Frequently asked questions
How many steps make one full revolution?
200 steps. All four motors use a 1.8 degree step angle, which gives 200 steps per revolution.
Does every motor include a gear?
No. Only the single NEMA 17 listing states a 20T MXL gear installed on the shaft. The other listings state no gear.
Does the steel bracket fit a NEMA 23 motor?
No. The bracket listing states it fits NEMA 34 stepper motors, with dimensions of 3.9 by 3.9 by 3.9 inches.
What voltage should each motor run at?
The single NEMA 17 listing recommends 12V, the 4-pack suggests 12 to 24V, and the 3.0Nm NEMA 23 recommends 24 to 48V.
Sources
Last updated: November 12, 2026.