Picking a stepper motor for CNC is about understanding your torque and RPM (speed) requirements.

The best stepper motor will be capable of delivering your required torque while also being fast enough.

It is easy to overpay with a too-large motor or to pick a feeble motor that quits on you when you really push it.

This guide can help you decide on the stepper motor you need for your CNC application.

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As a CNC hobbyist and consultant, I get asked for stepper motor recommendations by people looking to either build a CNC or replace the motor in their existing CNC.

I tell them my best picks depending on the category of the stepper motor:

• Best NEMA 17 Stepper Motor-STEPPERONLINE NEMA 17 Stepper Motor
• Best NEMA 23 Stepper Motor-STEPPERONLINE NEMA 23 Stepper Motor
• Best Closed Loop Stepper Motor (NEMA 23)-TOAUTO Integrated Closed-Loop NEMA 23 Stepper Motor with Driver
• Best NEMA 34 Stepper Motor-Hobby-Unlimited NEMA 34 stepper motor

Here are the best Stepper Motors available today [2023] for CNC applications.

Stepper Motor	Peak Current	Holding Torque
1. STEPPERONLINE NEMA 17 Stepper Motor	2A	84 oz.in
2. Usongshine NEMA 17 Stepper Motor	1.5A	60 oz.in
3. STEPPERONLINE NEMA 23 Stepper Motor	2.8A	178.5 oz.in
4. STEPPERONLINE NEMA 23 (3A) Stepper Motor	3.0A	269 oz.in
5. High Torque NEMA 23 4.2A Stepper Motor	4.2A	425 oz.in
6. TOAUTO Closed-Loop NEMA 23 Stepper Motor	3.0A	283 oz.in
7. RATTM Motor NEMA 23 Stepper Motor kit	4.0A	425 oz.in
8. Hobby-Unlimited NEMA 34 stepper motor	6.0A	1200 oz.in

Best NEMA 17 Stepper Motors

1. STEPPERONLINE NEMA 17 Stepper Motor– Best high precision stepper motor

Parameter	Value
Rated Current	2A
Holding Torque	84 oz.in
Compatible Driver	TB6600 or DM542T (or higher)

The STEPPERONLINE NEMA 17 motor is probably the most popular NEMA 17 stepper motor today, with good reason.

The holding torque on this motor is 84 oz.in, which is quite high for a NEMA 17 motor, and this will suit most desktop CNCs and Laser engravers.

In fact, it is ideal for 3D printers as well.

For perspective, most 30 x 18 desktop CNCs that are on the market today, such as the Sainsmart 3018 CNC run on stepper motors that have a holding torque of 35 oz.in and 1.3 A rated current.

The torque of these motors is more than double that of popular desktop CNCs. Thus this stepper motor is a great choice for most hobbyist CNCs.

But if you are going to run 8 ft. x 4 ft. full-size CNC routers, and not engravers, then I suggest you look into NEMA 23 stepper motors instead.

I talk in detail about the various Desktop CNC Router options over here-Best Desktop CNC Router Machines for Hobbyists

This motor can handle a maximum current of 2A per phase.

To run this stepper motor, you need a stepper driver that has a maximum current rating higher than 2 A.

The most popular and cost-effective ones that meet this criterion are the TB6600 driver and DM542T driver.

With this motor, you have the potential to build a desktop CNC that is more powerful and smooth than any under $500 desktop CNCs on the market.

However, you need to also match the right controller with this. Ensure that you either use a stepper driver like TB6600 or better with this 2A motor.

I say this because a lot of budget GRBL CNC controllers on the market have integrated stepper drivers, and most of them are either A4988 or DRV8825.

Technically, you can run this motor using an A4988 or DRV8825 stepper driver at low current, but you wouldn’t be able to extract the full performance of this motor.

Moreover, if you try to run this motor using those drivers at 2A, expect it to burn out after a while.

For those interested in how much torque this stepper motor will generate at different RPMs when driven at 24V, this can help- Torque v/s RPM Chart for NEMA 17 Stepper Motor.

This motor has a step angle of 1.8 degrees, and the step angle accuracy of this motor is +/- 5%

The inductance on this motor is 3.0 mH which is less than the recommended maximum inductance of 5.0 mH. This helps it achieve good torque even at higher RPMs.

This motor has an ambient temperature rating of 10-50°C and a maximum temperature rating of 80°C.

Almost all users of this motor report a temperature that’s under this rated temperature and only a bit warm when run at 1A current.

The excellent heat management of this motor helps it avoid missed steps, which happens when a stepper motor gets too hot.

This stepper motor comes with clear documentation on which of the four wires go where, and that’s really helpful if you’re not an expert.

If you want multiple NEMA 17 motors instead of just one, I suggest you opt for this set of 5 NEMA 17 motors for a bulk discount- STEPPERONLINE 5PCS Nema 17

PROS : 

• High torque among NEMA 17 motors.

CONS : 

• Needs TB6600 or better stepper driver.

2. Usongshine NEMA 17 Stepper Motor

Parameters	Value
Rated Current	1.5 A
Holding Torque	60 oz.in
Compatible Driver	A4988 or DRV8825 (or higher)

With 60 oz.in holding torque, the Usongshine NEMA 17 stepper motor is a solid bipolar stepper motor.

To run this stepper motor, you need a stepper driver that has a maximum current rating higher than 1.5 A. The most popular ones that meet this criterion are the A4988, DRV8825, and TB6600 drivers.

If you have a controller with integrated stepper drivers, just make sure it has a driver that is A4988 or better (in terms of Amps).

Whichever stepper driver you choose or already have, make sure to limit the current that flows from it to the motor to be below the rated current of the stepper motor, i.e. 1.5 A.

The length of the cable on this motor is 1 meter with four wires, which is standard for bipolar stepper motors these days.

This motor is a 1.8-degree stepper motor, meaning it will take 200 steps for every full revolution.

The step angle accuracy of this motor is +/- 5%, and most users report very minimal missed steps unless running at the highest amperage all the time.

The PCB boards in the motor compartment have been upgraded from previous versions to ensure the smooth motion of the motor. 

The whole surface of the motor is coated with epoxy resin which gives it higher stability and lower noise.

The Usongshine motor, like its housing, also has high stability, uniform speed of operation, and low noise.

The copper coils and the silicon steel rotor used in the motor evenly disperse heat.

The silicon steel rotor, along with the rubber-coated surface, makes sure that the output is stable, the noise is lower, and the lifetime of the product is longer. 

This motor runs at a temperature around 50°C when under normal loads and heats up to 70°C when run at its maximum rated current of 2A.

The manufacturer does not specify the inductance of this motor, but it is low, which gives this motor reasonable torque even at higher RPMs.

The low resistance also enhances the thermal conductivity of the motor, producing both better performance and reduced heat loss. 

Overall, this NEMA 17 stepper motor is a solid option for any desktop engraver, laser engraver, or 3D printer.

Pros:

• Good compatibility with budget stepper drivers and controllers.

Cons:

• Lower torque compared to the 84 oz.in StepperOnline NEMA 17 Motor.

Best NEMA 23 Stepper Motors

1. STEPPERONLINE NEMA 23 2.8A CNC STEPPER MOTOR

Parameters	Values
Rated Current	2.8 A
Holding Torque	178.5 oz.in
Compatible Driver	TB6600 or DM542T (or higher)

The STEPPERONLINE NEMA 23 stepper motor is overall the best pick among NEMA 23 stepper motors if you are looking for a motor that balances price and torque. 

The bipolar motor produces 178.5 oz.in of torque and has a fixed step angle of 1.8 degrees.

This stepper motor can do most tasks you need for a DIY CNC Router that cuts wood, plastics, aluminum, and PCBs.

As a benchmark, the highly popular Openbuilds Lead CNC (60 in. x 60 in. size) has a 175 oz.in NEMA 23 stepper motor, which resembles closely to this stepper motor.

Most 7-inch lathes and small mills, such as the Sherline Bench Mill, run with 170-280 oz.in torque.

This motor has a phase resistance of 0.9 ohms and is rated for 2.8A current per phase.

The 57x57x56mm body is made up of a mixture of steel, copper, metal, and aluminum.

This gives the motor durability, and also it weighs less compared to NEMA 23 motors of similar torque.

The StepperOnline NEMA 23 motor weighs 1.54 lbs (700g).

The motor is also capable of running at 1000 RPM at the no-load condition and has overall great efficiency for carving different materials.

You can run this motor using the TB6600 driver or DM542T driver.

Of course, you can use even better drivers if your application demands it.

The Driving Voltage required for running this stepper motor is 24-48V, which is standard for most NEMA 23 motors.

This motor has 4 lead wires with a 300 mm wire length.

The inductance on this motor is 2.5 mH which is quite low, enabling it to achieve high torque even at high RPMs.

PROS:

• Lightweight ( 700g )

2. STEPPERONLINE NEMA 23 3.0A Stepper motor-Best high speed stepper motor

Parameter	Value
Rated Current	3 A
Holding Torque	269 oz.in
Compatible Driver	TB6600 or DM542T (or higher)

This StepperOnline NEMA 23 Motor has the same size (form factor) as the 2.8A NEMA 23 motor above.

However, it has a 3A maximum current per phase and a 269 oz.in holding torque. This is higher than the 178.5 oz.in available in the 2.8A NEMA 23 motor.

The real question is, do you need it? It’s difficult to say if you need this without knowing how fast you want your machine to cut.

How fast the CNC moves is related to the feed rate, and that depends on your stepper motor RPM.

The problem is that the torque you get from a stepper drops off linearly when you increase the RPM, to make the router move faster.

For this NEMA 23 motor, you still get around 80% of its maximum torque, i.e around 226 oz.in at 400 RPM, when run with a 48VDC supply.

Torque v/s RPM Chart for 3.0A NEMA 23 Motor

If your application demands more than 400 RPM, and you need above 250 oz.in torque even at that speed, I suggest you go to the next motor in this list with higher torque.

This motor also has higher resistance (1.12ohms).

This motor can also be run using the TB6600 driver or DM542T driver stepper drivers. Of course, you can use even better drivers if your application demands it.

The Driving Voltage required for running this stepper motor is 24-48V, which is standard for most NEMA 23 motors.

This motor also has the same 4 leads but a longer shaft length of 21mm when compared to the previous NEMA 23, which has 20.6mm. 

PROS : 

• Produces higher torque 
• Affordable price 

3. High Torque NEMA 23 4.2A CNC Stepper motor-Best High Torque Stepper Motor

Parameter	Value
Rated Current	4.2 A
Holding Torque	425 oz.in
Compatible Driver	DM542S (or higher)

This is really the monster among NEMA 23 motors and is a high-torque stepper motor.

With a 4.2A rated current per phase and 425 oz.in holding torque, this stepper motor is usually the biggest you find in any CNC Router that cuts materials like wood, plastics, aluminum, and PCBs.

You go higher than this only if you want to do some serious metal machining. Even then, it might not really be necessary.

A lot of larger lathes (10″ x 22″ or 10″ x 32″) and heavy benchtop mills ( X and Y axis) have their torque between 400-600 oz.in.

This motor has a really impressive torque v/s RPM curve.

If you look at the curve, it delivers 283 oz.in torque even at 360 RPM when run using a 36V supply. You can expect even more power with a 48VDC.

This stepper motor can be run at moderate speeds using a DM542T driver, while a TB6600 might be too weak for this motor.

If you want to really push this motor to its limit, i.e 4.2A, you should get a driver that can handle at least 5A, like the DM542S (5.0A) or the DM556 (5.6A) or the Trinamic TMC5160 (included in the xPro V5 controller).

The motor has a 1.8 degrees step angle with four wires. The lead length on the wires is 400 mm (40 cm).

As you can expect, this motor is quite heavy for a NEMA 23. It weighs 4 lbs (1.8kg).

The power supply for this motor should be in the range 24-48VDC.

This motor has a maximum rated temperature of 80°C. In case of overheating issues under normal working conditions, consider upgrading your stepper motor drivers.

Overall this is what you need if you want absolute muscle at the size of a NEMA 23.

PROS :

• Very high torque even at high RPM.
• Almost never misses a step even after long use.

CONS : 

• Heavy and needs 5A drivers for full performance.

4. TOAUTO Integrated Closed-Loop Nema23 Stepper Motor with Driver-Best Closed Loop Stepper Motor

Parameter	Value
Rated Current	3 A
Holding Torque	283 oz.in
Compatible Driver	Integrated Driver

The TOAUTO NEMA 23 Stepper Motor is a good choice if you want a closed-loop Stepper Motor instead of an open-loop stepper motor.

The closed-loop stepper motor has a high holding torque of 283 oz.in. The 36V 5A-rated driver accompanies the motor, so you do not need to look for a compatible stepper driver.

All the other motors listed above are open-loop motors. Open-loop motors suffer from a lack of feedback to the controller.

One solution is to use a servo motor instead of a stepper motor. However, they cost significantly more.

A budget solution is to use a closed-loop stepper motor.

The biggest advantage in choosing a closed-loop stepper motor is that it gives feedback to the controller similar to a SERVO motor at almost 1/3rd the price of a SERVO Motor.

Open-loop stepper motors can sometimes miss steps, especially when run at their maximum current limits with the motor getting too hot.

The additional feedback that is given to the controller in a closed-loop stepper motor, gives the stepper motor a chance to either correct its position or stop after each move in case there are missed steps.

If you are doing critical work, where a missed step can ruin your workpiece, then a closed-loop stepper motor might be a better option for you.

It alerts you regarding the missed step and stops moving so that you can make changes in the input.

A closed Loop stepper motor also runs cooler than an equivalent torque Open-loop stepper motor because it detects the actual load and regulates the current supply as per requirement.

At the stop position (0 RPM), it almost stops supplying current resulting in no heat, while an open-loop stepper motor is at its hottest when in the stop position.

The real-time synchronization of the hybrid step-servo system provides feedback for very quick start and stop, zero speed stop stability.

The position-tracking technology used in the real-time closed-loop system ensures that there is no loss of synchronization. It works by positioning a position encoder behind the step motor.

The position encoder makes sure that the degree of stepping or positioning is as accurate as possible. The encoder also applies an encoding and filtering technique to overcome the resonance problem.

This results in smooth and accurate motion at low speed and overcomes the noise and vibration problems encountered by traditional stepper motors. 

The hybrid servo drive system applies a current control technique which results in a 30% speed performance increase and improves the effective torque by 70%. The combined effect is high torque operation at high speed. 

This motor driver system does not require any additional setup and is plug-and-play like other stepper motors.

PROS : 

• Position tracking technology provides better real-time synchronization
• Comes along with the stepper driver 
• Does not heat up much

CONS : 

• The NEMA 23 motor would have 0.25 inch shaft while this stepper motor has 0.327 inch shaft, hence it is more like a NEMA 24 
• Pricier than other NEMA 23 motors.

5. RATTM Motor 4 Axis CNC NEMA 23 Stepper motor kit

Parameter	Value
Rated Current	4 A
Holding Torque	425 oz.in
Compatible Driver	FMD2740C (or higher)

If you want stepper motors for your CNC and you don’t want to bother with finding compatible stepper drivers and power supply, then this kit is for you.

This CNC stepper motor kit comes included with 4 powerful NEMA 23 stepper motors, an FMD2740C stepper motor driver, controller, power supply, and a breakout board. 

The kit features a NEMA 23 stepper motor which is able to produce a holding torque of 425 oz.in with a step accuracy of 5%.

The resistance and inductance accuracy of 10 and 20 percent respectively makes sure that the motor follows a fixed step angle of 1.8 degrees.

The switching power supply has a wattage of 400W and is a single output producing 36V / 9.7A, while the input is 100 – 120 V AC or 200 – 240V AC.

The USB CNC breakout board provides an easy connection via USB. The board has a high-performance motion controller providing exceptional control of the motor.

The only downside to this is that since it is a USB-connected board, it only works with pc board software like windows 7. Meaning Mach3 cannot be used.  

PROS : 

• All in one kit and no need to check for additional compatible drivers and supplies.

CONS : 

• Mach3 is not supported.

Best NEMA 34 Stepper Motors

1. Hobby-Unlimited NEMA 34 Stepper Motor-Best NEMA 34 Stepper Motor

Parameter	Value
Rated Current	6A
Holding Torque	1200 oz.in
Compatible Driver	DM860T (or higher)

This is a NEMA 34 Stepper motor with 1200 oz.in holding torque and a rated maximum current of 6A per phase.

The holding torque on this is three times that of the previous NEMA 23 motor with a 4.2A rating.

This motor is suitable for the Z-axis of heavy benchtop mills.

A single motor of this size can theoretically lift 75lb weight, and this stepper motor is the definition of a heavy-duty stepper motor.

The only reason why you’d need this motor for DIY CNC Router is if you want to run constant production work and need the bit of extra edge you get from the higher power.

However, the extra power comes at a cost. You need bigger mounting brackets for this motor.

Also, check whatever application you are using the motor for has the space for a motor of size 86 x 86 mm with 114 mm length.

If you need to use a motor as powerful as this, make sure the rest of your mechanical system supports it.

You need a highly rigid and strong chassis that can take the high torque this motor produces.

If you run this on a weak mechanical system that can’t handle the stress, the whole setup can crumble and cause damage.

To run this motor you need a driver capable of delivering more than the 6A.

The DM860T Stepper Driver is a good choice for this motor. It is built to run NEMA 34 and NEMA 42 motors, with a current range of 2.4-7.2A and 18-80V AC or 36-110V DC power supply.

This NEMA 34 motor has four lead wires and weighs a whopping 7.5 lbs (3.4 kg).

With a body made of steel, the heavy-duty HobbyUnlimited stepper motor is built to last a long time.

The motor produces a high holding torque of 1200 oz.in through its long 14mm shaft with a 5mm keyway.

The motor has a fixed step angle of 1.8 degrees and a step accuracy of 5 percent.

The motor also works at an ambient temperature range of 20°C to 50°C (approximately). 

PROS : 

• High torque 
• Durable body built to last  

CONS : 

• Heavy- 3.6 kg 

Things to consider before choosing a Stepper Motor for your CNC

NEMA Sizing

Generally, as the NEMA sizing number increases, the power and torque of the motor also increase.

However, check the size of the motor and ensure that it fits your application.

Overbuying

It is easy to overbuy stepper motors. Any excess capacity in terms of torque above a safe margin is a waste that will never be used.

You will need to spend more on the power supply, stepper driver, and controller for extra torque you don’t really need.

Torque and RPM

First estimate the torque and RPM you need for your application and work from there to determine everything else you need, like stepper drivers, power supply, and controllers.

As the RPM of a stepper motor increases, the torque drops in the stepper, almost proportionately.

This can be compensated by applying a higher input voltage through the stepper driver.

However, this means you need to manage the increased heat through some cooling mechanism.

Inductance

Motors with low inductance have better torque at higher RPMs. As a thumb rule, motors with inductance below 5mH are to be preferred.

Heat Produced

More current in the motor means more heat. As a general thumb rule, every 10% reduction in current results in a 20% heat reduction.

Power Needed

Say you have four stepper motors requiring 2.8A. This means that a total of 4 x 2.8 = 13.2A is required.

If 24V is the rated voltage then the rated power will be V*I = 24 x 13.2 = 316.8W. So here in this case a 350W 15A supply would work great.

Frequently Asked Questions (FAQ)

What size stepper motor should you use for a CNC router?

Stepper motors used in a CNC router are generally NEMA 17 or NEMA 23 or NEMA 34 stepper motors with a holding torque between 30 oz.in (NEMA 17) and 1000 oz.in (NEMA 34).

• NEMA 17 stepper motors are used in CNC engravers and small desktop CNC routers
• NEMA 23 stepper motors are used in most hobbyist CNC routers.
• NEMA 34 stepper motors are used in production-grade CNC routers and heavy benchtop CNCs.

The NEMA number refers to the frame size of the stepper motor and does not directly indicate the mechanical capabilities of the motor.

Which is better servo or stepper motors?

Servos motors are better for applications requiring high precision and need high torque even at high speeds. However servo motors are more complex, run in closed-loop, and are expensive compared to stepper motors. Stepper motors are open-loop and much lower in cost. Stepper motors are ideal for hobbyist and non-industrial applications.

How long do stepper motors last?

Stepper motors typically last around 5 years of use. Most stepper motors are tested to run for 10,000 hours, and considering the typical use case, it could last 5 years.

What are the disadvantages of stepper motors?

The disadvantages of stepper motors are that the torque falls off rapidly with increasing RPM, and this might make them useless for applications requiring high speed with high torque output.