The NEMA17 stepper motor is the workhorse of 3D printers, CNC machines and robotics. But not all NEMA17 motors are the same — pick the wrong one and your printer skips steps or your CNC stalls. Here's how to choose the right one.
What “NEMA17” actually means
NEMA17 refers only to the frame size — a 1.7 inch (42mm) faceplate. It says nothing about torque, length or wiring. Two NEMA17 motors can have very different power, so always check the specs below.
1. Holding torque (the most important number)
Measured in kg-cm (or N·cm), holding torque is how much force the motor resists when powered and stationary. As a rough guide:
- ~4 kg-cm — great for most 3D printer axes (X/Y/Z) and light robotics. See our NEMA17 4.2 kg-cm stepper.
- ~6–7 kg-cm — for heavier gantries, CNC axes and extruders under load. See our NEMA17 6.5 kg-cm stepper.
2. Step angle
Almost all NEMA17 motors are 1.8° per step (200 steps/revolution). With microstepping drivers you get far smoother, quieter motion.
3. Shaft type
A D-type (flat) shaft stops pulleys and couplers slipping under load — preferred for belt-driven printers and CNC. Round shafts are fine for gears with grub screws.
4. Driver compatibility
NEMA17 motors are bipolar and pair with common drivers — A4988 and DRV8825 (cheap, reliable) or TMC2208/2209 (near-silent). Match the driver's current rating to the motor's rated current.
Quick picks
- 3D printer (most builds): 4.2 kg-cm, 1.8°, D-shaft
- CNC / heavy gantry / extruder: 6.5 kg-cm, 1.8°, D-shaft
All stepper motors ship fast from our Bengaluru warehouse with a GST invoice on request. Not sure which torque you need? WhatsApp us at +91 78285 34155 and we'll help you spec it.