NEMA 34 Stepper Motor: High-Torque 86mm Frame for Heavy CNC
The NEMA 34 stepper motor is the high-torque workhorse for heavy CNC and industrial automation. With an 86mm × 86mm faceplate, it delivers several times the torque of a NEMA 23, which is why it drives large router and plasma gantries, lathe axes, and heavy positioning systems. A 2-phase NEMA 34 hybrid stepper motor delivers holding torque from about 2.3 N·m up to 12 N·m depending on body length, at a 1.8° step angle. The NEMA 34 size (often written nema34) is fixed at an 86mm faceplate, with body length the main variable that sets torque.
Key Specifications at a Glance
| Parameter | Specification |
|---|
| Frame Size | 86 × 86 mm |
| Step Angle | 1.8° (200 steps/rev), 0.9° optional |
| Phase | 2-phase (bipolar) |
| Holding Torque | 2.3–12 N·m |
| Rated Current | 4.0–6.0 A/phase |
| Body Length | 67–118 mm (varies by model) |
| Shaft | 14mm standard |
| Lead Wires | 4-wire or 6-wire
|
Typical Applications
The NEMA 34 is the frame to reach for when a NEMA 23 runs out of torque. Common applications include:
- Heavy CNC routers and mills — CNC NEMA 34 builds use large gantry and table drive.
- Plasma and laser cutters — big-format gantry systems.
- Lathe and machining — spindle indexing and feed axes.
- Heavy automation — large conveyors, lifts, and indexing tables.
- Robotics — base and joint drive on larger machines.
- Industrial positioning — winders, presses, and feed systems.
With a NEMA 34 gearbox the same frame drives a linear actuator or a low-speed, high-torque axis; a dual-shaft version adds a rear shaft for an encoder or a second load. Mounting brackets are available for easy machine integration.
NEMA 34 vs NEMA 42: Which One Do You Need?
The next size up from NEMA 34 is NEMA 42 (110mm × 110mm). Here is a quick comparison:
| NEMA 34 (86mm) | NEMA 42 (110mm) |
|---|
| Faceplate | 86 × 86 mm | 110 × 110 mm |
| Max Holding Torque | ~12 N·m | ~28 N·m |
| Weight | 1.4–3.8 kg | 4–8 kg |
| Best For | Heavy CNC, high-torque axes | Largest axes, maximum torque |
If your load needs more than about 12 N·m, move up to NEMA 42. For most heavy CNC and automation within 12 N·m, NEMA 34 is the right fit — and far more common and easier to source than NEMA 42.
Customization Options
Cymotorix NEMA 34 stepper motors can be customized for OEM integration. As a NEMA 34 stepper motor manufacturer and supplier, we produce them to your specification. Common modifications include:
- Shaft diameter and length adjustment (standard shaft is 14mm)
- D-cut, flat, or keyed shaft for direct coupling
- Dual-shaft output for a rear encoder or second load
- Custom lead wire length and connector type (JST, Molex, bare leads)
- Winding parameters modified to match your driver voltage and current
- 0.9° step angle for finer resolution
- Rear-shaft extension for encoder mounting
- Mounting bracket for machine integration
- Planetary, worm, or right-angle gearbox integration for higher output torque at low speed
How to Drive a NEMA 34 Stepper Motor
NEMA 34 motors are 2-phase bipolar steppers, so they run on a standard 2-phase stepper driver — but a high-current one. Rated current is around 4.0 to 6.0 A per phase, so the driver must handle that with headroom. We can supply a driver matched and set to the motor if you want the pair tested together.
Recommended supply voltage is 48–80VDC. A NEMA 34 has higher winding inductance than smaller frames, so a high bus voltage is important to push current in fast and hold torque at speed. Set the driver's current limit to the motor's rated current so the windings don't overheat.
