Hybrid stepper motor
NEMA 17 High Torque (M42STH) hybrid stepper motor
42 mm 2-phase hybrid stepper with 18 standard windings from 29-60 mm long, the general-purpose size for CNC, 3D printing and robotics.
Key specifications
| Frame sizes | 42 mm |
|---|---|
| Feedback | none (open loop); optical encoder option |
| Current (max) | 1.7 A |
| Holding torque | 0.18–0.7 Nm |
| NEMA sizes | 17 |
| Step angle | 1.8 ° |
| Step angle options deg | 1.8, 0.9 |
| Rated current range | 0.3-1.7 |
| Rated voltage range | 2.2-12 |
| Length range | 29-60 |
| Leads | 4, 6 |
| Phases | 2 |
Series ranges as published; individual models vary. The full datasheet, drawings and CAD models are available on request.
Options
- single or double shaft
- optical encoder
- planetary gearbox
- 0.9 deg custom
- custom windings
- alternative mounting flanges
Typical applications
What a hybrid stepper motor is
A hybrid stepper motor moves in fixed angular steps, typically 1.8° or 200 full steps per revolution, as a drive switches current through its windings in sequence. It combines a permanent-magnet rotor with toothed iron stator and rotor sections, giving high holding torque and fine resolution. With a microstepping drive, each full step is split into smaller steps for smoother motion. Steppers usually run open loop, so position is known by counting steps rather than measured.
When engineers choose a hybrid stepper motor
Choose a hybrid stepper for low-cost, simple positioning at low to moderate speed, such as indexing, dosing, small axes and instruments. It holds position strongly at standstill and needs no tuning. The trade-offs are falling torque at speed, resonance and possible lost steps if overloaded. Where speed is high, loads vary or a missed position would cause a fault, a closed-loop stepper or servo is safer.
How to specify the NEMA 17 High Torque (M42STH)
Send these with your enquiry and an engineer can confirm the right NEMA 17 High Torque (M42STH) variant:
- Holding torque (Nm)
- Torque needed at operating speed (Nm at rpm)
- Frame size (NEMA or mm)
- Step angle (°)
- Phase current and inductance (A, mH)
- Drive voltage (V)
- Shaft, encoder and IP options
Common mistakes to avoid
- Sizing on holding torque instead of the pull-out curve
- Driving with too low a supply voltage, losing high-speed torque
- Leaving out torque margin, typically 30% to 50%
- Ignoring resonance in the mid-speed range
NEMA 17 High Torque (M42STH): frequently asked questions
What is the NEMA 17 High Torque (M42STH)?
42 mm 2-phase hybrid stepper with 18 standard windings from 29-60 mm long, the general-purpose size for CNC, 3D printing and robotics. Published series figures include frame sizes 42 mm, current 1.7 A, holding torque 0.18 Nm, holding torque 0.7 Nm. It is available through our supply network, and our engineers can confirm the right variant for your application.
Who makes the NEMA 17 High Torque (M42STH)?
The NEMA 17 High Torque (M42STH) is part of a range available through our supply network. Send us your requirement for pricing, lead time, datasheets and CAD.
What is the frame sizes of the NEMA 17 High Torque (M42STH)?
The published series maximum frame sizes is 42 mm. Individual models and sizes in the NEMA 17 High Torque (M42STH) range vary, so check the exact variant against your duty cycle, mounting and environment, or ask our engineers to confirm the right size for you.
Why do stepper motors lose torque at high speed?
Winding inductance limits how fast current can rise each step. As speed increases there is less time per step, so current and torque fall. A higher drive voltage raises current faster and extends the torque curve. Always size from the pull-out torque curve at your drive voltage.
Does microstepping increase accuracy?
Microstepping makes motion smoother and gives finer resolution, but accuracy is not improved in proportion. Each microstep produces only a small torque increment, so load torque can shift the actual position. Accuracy is mostly set by the motor's step accuracy and the load.
Further reading: How to select a stepper motor · Servo vs stepper · Servo and stepper motors
Other hybrid stepper motor series
Spec builder
Configure NEMA 17 High Torque (M42STH)
Select every part you need, answer the questions an applications engineer would ask, and see your summary before we ask for any details.
- 1Products
- 2Performance
- 3Environment
- 4Volumes
- 5Your spec
Engineer support
Need NEMA 17 High Torque (M42STH) or a complete system around it?
Tell us what you need, whether it is this part, an equivalent or a complete axis built around it. An engineer will review your requirements and reply, normally within one working day.
- Reviewed by an engineer, not an autoresponder
- Like-for-like and better-fit alternatives
- Standard, modified and custom options
Prefer to configure it? Use the spec builder.