Best Air Die Grinders

Updated September 2020
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BestReviews spends thousands of hours researching, analyzing, and testing products to recommend the best picks for most consumers. We only make money if you purchase a product through our links, and we never accept free products from manufacturers. Read more  
BestReviews spends thousands of hours researching, analyzing, and testing products to recommend the best picks for most consumers. We buy all products with our own funds, and we never accept free products from manufacturers.Read more 
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Why trust BestReviews?
BestReviews spends thousands of hours researching, analyzing, and testing products to recommend the best picks for most consumers. We only make money if you purchase a product through our links, and we never accept free products from manufacturers. Read more  
BestReviews spends thousands of hours researching, analyzing, and testing products to recommend the best picks for most consumers. We only make money if you purchase a product through our links, and we never accept free products from manufacturers. Read more  
BestReviews spends thousands of hours researching, analyzing, and testing products to recommend the best picks for most consumers. We buy all products with our own funds, and we never accept free products from manufacturers.Read more 
How we decided

We purchase every product we review with our own funds — we never accept anything from product manufacturers.

19 Models Considered
6 Hours Researched
1 Experts Interviewed
201 Consumers Consulted
Zero products received from manufacturers.

We purchase every product we review with our own funds — we never accept anything from product manufacturers.

Buying guide for best air die grinders

Last Updated September 2020

Air die grinders are remarkably versatile tools. You’ll find them in garages and workshops everywhere, used for everything from shaping plastics to carving wood to polishing metal.

Air die grinders have no motor of their own — they’re powered by a compressor. That means the unit can be more compact and lighter while producing equivalent or greater power than their electric counterparts. There’s also less that can go wrong, which results in minimal maintenance.

Given the advantages, it’s no surprise that air die grinders are very popular, and manufacturers have responded with dozens of different models for you to choose from. That’s great, but it can make it challenging to find the best tool for the job you need to do. Is a budget grinder up to the task, or do you need to invest in a pro model?

The BestReviews team has been finding answers so we can help you make the right buying decision. Our recommendations showcase the kind of price and performance options available, and in our comprehensive buying guide we look at technical issues and how to get the most from your tool.

The metal bodies of these devices can be uncomfortable (and cold) over long periods. Wearing gloves is recommended.

Key considerations

What air die grinders can do

Perhaps paradoxically, an air die grinder (also called a pneumatic grinder) owes much of its versatility to its simplicity. Basically, it’s a tool with a head that rotates very fast, but because you can fit it with many different bits, it can be used to sculpt, cut, grind, or polish all kinds of materials.

That being the case, you’ll find them in the shops of professional woodworkers, engineers, auto technicians, welders, and a host of other trades and crafts. They’re also very affordable, which helps to make them suitable for people with home workshops that already have a compressor or who are thinking of investing in one.

EXPERT TIP

If you’re into large-scale woodcarving, a die grinder and a set of burrs offer both rapid material removal and high precision.


Staff  | BestReviews

Features

Almost all air die grinders have a similar design: a steel or aluminum body has a lever trigger/throttle on the side. It’s a simple and ergonomic design. You wrap your hand around it and squeeze. The only disadvantage is that it’s easy to operate accidentally, or when you put the tool down, and that could be dangerous. Good models have a safety lock to prevent this happening.

Tool head

The tool head is either straight (in line with the body) or at a 90° angle. Which is the better choice very much depends on the work you need to do. An angled head can get into spaces a straight one might not, but the straight tool is often preferred for precision. If you can’t decide, or you think you need both, there are some very cost-effective twin-packs available.

Power

It can be difficult to assess power, and often figures aren’t easy to find. Sometimes the horsepower (hp) is given, but it doesn’t mean much when a 1/4 hp tool is quite powerful in these circumstances. The best indication is air consumption, given in cubic feet per minute (CFM). Generally, this runs from around 1.5 CFM for pencil-grip precision air grinders, to 6 CFM for heavy-duty models. For the technically minded, it’s not air pressure — which is probably a constant 90 pounds per square inch (psi) — it’s actual volume of air.

Speed

You’ll also get speed ratings, usually between 20,000 and 25,000 revolutions per minute (rpm) Precision types go higher. It’s important to note that this is “free speed,” in other words, without a bit attached, because the type of bit (and the material you’re working on) will make a huge difference to actual operating speed. That’s where the difference in CFM will make itself felt, with higher airflow providing increased drive.

Insulation: High rotational speeds can make air die grinders vibrate quite a lot. Not a problem if you’re only using one for short periods, but uncomfortable if you’re working with it all day. Some of the top models have rubber casings that provide insulation. With those that don’t, it’s worth checking customer feedback to see if real-world users think it’s a problem.

Collet

Most air die grinders have a 1/4-inch collet. The range of bits available is enormous. However, for delicate work, a bit with an 1/8-inch shank might be preferred. Some air grinders come with an optional 1/8-inch collet, but not all, and adapters may or may not be available, so this is actually quite an important factor.

Exhaust valve

An exhaust valve is necessary to allow the air to escape. Where this is positioned is another point to consider. You don’t really want it in your face, but having fast-moving air blowing across the workpiece might be a problem. Having said that, for someone else, having the debris blown away could be a bonus!

Weight

Although none of these tools is particularly heavy, the weight is worth thinking about if you’re using one for long periods. It will also have a minor impact on maneuverability.

EXPERT TIP

Although air tools are less complicated than electric power tools, because they have no motor, the same is not true of your compressor. Make sure it gets regular maintenance.


Staff  | BestReviews

A note about safety

Compressed air doesn’t seem dangerous, but it can be lethal. If a tool is pressed against the skin, air can penetrate and cause an embolism — an air bubble in the bloodstream. If it reaches your heart, it can kill you. Used properly, there isn’t any risk, but never mess around with these tools. Take the same precautions with an air die grinder that you would with any power tool. Wear gloves, safety glasses or a face shield, and respiratory protection appropriate to the task you’re performing. Compressors and die grinders can be noisy, so earplugs may also be needed.

Accessories

Disc holder: Protool Roloc Disc Pad Holder
This is a cheap but indispensable tool for increasing the versatility of your air die grinder. A hard-wearing rubber pad with a 1/4-inch steel shank accepts 3-inch-diameter disposable sanding, grinding, and polishing pads. Screw-in fitting ensures you don’t get the fly-off problems associated with hook-and-loop pads. A 2-inch version is also available.

Mandrel: Weiler 56490 Mandrel for Type 1 Cutoff Wheels
Another low-cost accessory. Takes 3-inch aluminum oxide cutoff wheels used to slice through plastic, fiberglass, iron, and steel. Made of tough carbon steel, with a standard 1/4-inch shank, this mandrel accepts wheels from 1/16- to 1/4-inch thick.

Grinding burrs: Osidu Carbide Rotary File Set
Made from extremely hard tungsten carbide blanks, these high-quality burrs have a unique double-cut tooth angle that grinds metal and wood with remarkable efficiency and stays sharper longer. There are ten different shapes and sizes, each with a 1/4-inch shank, supplied in a convenient stand.

EXPERT TIP

Air die grinders can generate a lot of torque. Make sure you have a good grip when you pull the trigger.


Staff  | BestReviews

Air die grinder prices

Inexpensive: The cheapest air die grinders we found cost around $20. They offer good value and adequate performance for the occasional user.

Mid-range: Between $30 and $60, you’ll find a wide choice of durable, high-quality tools for home and trade use, including models from many of the industry’s leading names. Few users will need to spend more.

Expensive: Heavy-duty and specialized air die grinders can exceed $60 (long-reach models, for example), but of the dozens we looked at, only one tool topped $100.

Auto enthusiasts will love an air die grinder. It can remove rust and old paint quickly and reach into areas where you’d never get the usual dual-action sander.

FAQ

Q. What’s the difference between an air die grinder and a rotary tool?
A.
In a nutshell, performance. While they both do similar jobs in terms of providing drive for various rotating bits, a compressor-driven die grinder is much more powerful than the electrically powered rotary tools from Dremel and similar devices.
 

Q. What about the difference between an air die grinder and an angle grinder?
A.
OK, the angle grinder is another step up in terms of power: rotary tool, die grinder, angle grinder, if you like. However, the angle grinder is limited to circular discs, and because of its high performance, mostly requires two hands to hold it. The die grinder is a more versatile tool, easier to control, and capable of greater precision.
 

Q. How do I know if my compressor is big enough to handle an air die grinder?
A.
All these tools (in fact, all air-powered tools of any kind) should have a CFM (cubic feet per minute) rating, which is the amount of air they consume while operating. If your compressor matches or exceeds that figure, you’re good to go.

Other Products We Considered
The BestReviews editorial team researches hundreds of products based on consumer reviews, brand quality, and value. We then choose a shorter list for in-depth research and testing before finalizing our top picks. These are the products we considered that ultimately didn't make our top 5.
The team that worked on this review
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    Bob
    Writer
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    Editor
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    Digital Content Producer
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    Web Producer

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