If you ever worked with any metal or har material in general, you surely could have benefited from using the best pneumatic die grinder for the task at hand. A die grinder is by far the most versatile tool any workshop can have, and good tools make or break a workshop.
We are going to talk about what makes these air tools so good, and what kind of performance you can expect. Additionally, we will talk about die grinder parts, mechanics, and ultimately their differences. We encourage you to study our guide and reviews and decide upon the right die grinder for your workshop after that. After all, you will be using this tool a lot, no matter the project or material you are going to work on. Let’s dig in!
What is a Pneumatic Die Grinder and Who Needs One?
To call these tools just die grinders does them no justice. The best way to describe them would be to say that pneumatic die grinders are, at their core, multi-functional pneumatic rotary tools. Now, we are aware that that sounds like quite a bit, but everything is in the name. The pneumatic part refers to the fact that this tool needs a pressurized air source to work. And what better place to make and store that pressurized air than an air compressor.
Why do engineers think that this is not a tool that only grinds die and metal parts? Well, the multi-functional part of the description should answer this. Pneumatic die grinders have so many purposes and functions thanks to the many extensions and burr bits you can attach to them (or insert into them, depends who you ask). That is why these tools are capable to grind, cut, polish, clean, sheer and do a lot more than “grind the die.”
Lately, with the rise of DIY workshops, and garage tinkering trend, the demand for well-built pneumatic die grinders are starting to rise. And die grinder use is not limited only to engineers and heavy-duty operators because die grinders proved useful in plastic arts as well. Artists, precisely sculptors, realized the precision and quality a pneumatic die grinder can provide in shaping and reshaping metal, mineral, and even plastic materials.
So, to answer the question of “What is a pneumatic die grinder?” the safest bet would be to say that it is an all-around tool that is versatile and handy as far as you can think of. Many experienced handymen and artisans around the world are still discovering new applications for this tool, even though it has been here for a century.
Best Pneumatic Die Grinders Comparison Chart
Ingersoll Rand 301B Air Angle Die Grinder
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Chicago Pneumatic CP875 1/4-Inch 90 Degree Angled Air Die Grinder
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DEWALT DWMT70783 Straight Die Grinder
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Ingersoll Rand 1/4″ Air Die Grinder 3107G
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Astro 218 1/8-Inch Pencil Type Die Grinder
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Best Pneumatic Die Grinder Reviews (Updated List)
1. Ingersoll Rand 301B Air Angle Die Grinder
The Ingersoll Rand air tools have been in the game for quite some time, and their angled die grinder is popular among amateurs and professionals alike. This is due to its compact design and a total weight of barely over one pound. Now, this model shows us that despite the lightweight it can be powerful, or even one of the most powerful tools in its range.
Its housing is made of aluminum, which is cast in an ergonomic shape, meaning no rubberized parts. The position of the drilling bur is set at an angle of 90 degrees, which allows better maneuvering and more comfortable reaching of hard-to-get spots. However, with powerful performances comes a great CFM need. This particular pneumatic die grinder requires 6 CFM on average, and 24 CFM at max load, so keep in mind that no light-duty air compressor can support it fully.
2. Chicago Pneumatic CP875 1/4-Inch 90 Degree Angled Air Die Grinder
This is a well-known pneumatic die grinder with an angled tip from CP. It is an air tool that can tackle any job from simple paint scraping to metal sheering and cutting. The housing is made of durable, lightweight aluminum, and it weighs a total of one pound, which is excellent for moving around.
The burr angle is perpendicular to the rest of the tool, which is especially popular with delicate work, not only with metal but with wooden materials as well. This Chicago pneumatic die grinder comes packed with a couple of wrenches to help you change the burrs, and it has an installed lock throttle, which prevents unwanted starts, thus increasing the safety of the model.
The collet size clocks at ¼ of an inch, which can fit most standard extensions and burrs. The CP875 is an excellent addition to your toolshed’s arsenal, and it surprised us with its power.
3. DEWALT DWMT70783 Straight Die Grinder
DEWALT is a renowned tool industry giant, and their straight die grinder has a lot to offer. It is a bit heftier than the grinders from its class, and it bears the recognizable black and yellow color of the manufacturer. The body is made of aluminum, which decreases the total weight of this air tool to only 2 pounds.
The exhaust pipe is put on the back, so there will be no unnecessary spraying of dust around. This particular pneumatic die grinder model is designed to fit two types of collets, specifically the 1/4 -inch and the 1/8-inch ones. To make things even more convenient, it has a touch control trigger, which is adjustable when it comes to rotation speed. Underneath the trigger, there is a safety throttle lever that will lock out the air tool if you let it out of your hand. All in all, it is a powerful and safe tool for its price.
4. Ingersoll Rand 1/4″ Air Die Grinder 3107G
The Ingersoll Rand tends to create versatile tools all around, and this die grinder model is one of the most compacts out there. But that does not mean that it lacks in power. The casing is aluminum-made and, around the ergonomic handle, there is a thick layer of rubber to prevent excess vibrations, and help with a stronger grip overall.
The burr angle of this particular pneumatic die grinder is at 0 degrees, meaning that you will be able to use it as a saw, with the right extensions to be exact. The trigger is activated by pushing the side, and under it, there is a safety lock installed, so you can lock it when you’re not using it.
Inside the collet of this model, you can fit a ¼ extension. The excess exhaust pressurized air is let out on the back, so sudden dust clouds are prevented.
5. Astro 218 1/8-Inch Pencil Type Die Grinder
This Astro pneumatic die grinder is not a regular one. It is designed to reach extremely hard to reach places. The incredible design and lightweight material enabled this air tool to weigh only 16 ounces, which is far below average even for this type of machine.
What makes this air die grinder exceptional is the fact that it can maintain a 56,000 RPMs with ease, regardless of its size. The collet slot is 1/6-inch in diameter, so any standard extensions from this range will do the job.
Additionally, the tool has a twist throttle control that allows you to switch between different rotating speeds, thus adapting to the task at hand in an instant. This pen die grinder is ideal for people who work with engine maintenance, or any heavy-duty machining. It can reach more than a standard die grinder, but it packs a punch of a larger one.
6. Ingersoll Rand 3101G Edge Series Pneumatic Angle Die Grinder
Ingersoll Rand has made tools for every experience and skill level you belong to, with this pneumatic die grinder appealing more to the people that value safety and stability. The aluminum casing makes the model ultra-lightweight, and the added anti-vibration ergonomic handle is coated with a rubber layer which furtherly increases grasp balance.
The burr is perpendicular to the unit, which is great for angle work and some hard-to-reach places. This angle die grinder can fit a ¼ burr extension of any kind in its collet, and we found it quite useful doing polishing of all sorts. The pressure is applied with ease thanks to the shape and firmness this unit has.
However, this pneumatic die grinder can also tackle some heavy -duty tasks. The trigger is adjustable, and it has a safety break under it, so it won’t trigger if it’s not held.
7. Chicago Pneumatic CP860 Heavy Duty Air Die Grinder
Here we have a CP pneumatic die grinder that is very popular with professional machinists and engineers. It has an industrial design, with a metallic finish and housing made entirely out of aluminum, which makes it heavy-duty and lightweight at the same time. The total weight of the tool is 1.26 lbs.
As opposed to air die grinders from its class, this model has a squared design of the handle, which makes it extra secure. The trigger is adjustable to the task, and it has a throttle break installed beneath it. The burr position is at a zero degree, making this pneumatic die grinder ideal for cutting heavy metals since you can attach a circular saw instead of a standard drill burr.
The gas exhaust is set at the back, so you do not have to worry about dust blowouts or spark dispersing while you work with metal.
8. Astro 219 ONYX Pneumatic Die Grinder Kit
This two-piece pneumatic die grinding set found a place on our list due to its wide range of purposes. Astro went with a modern design with a black and red color finish. The set consists of a 0-degree and a 90-degree air die grinder, which is covering everything this tool is supposed to cover. With the 0-degree tool, you can tackle sawing, cutting and sheering, while de 90-degree one can help you cover cutting some tight spots and high-end polishing.
Each die grinder weighs just under 2 pounds and has a composite handle which makes gripping much firmer. Additionally, the manufacturer put in a set of 8 different burr extensions to help you achieve ultimate precision. Both units have an exhaust at the back, and the power is controlled via a side trigger. Also, both die grinders have a safety throttle under the trigger which turns off the tool if the pressure is off of it.
9. Chicago Pneumatic CP872 Air Die Grinder
One of the more robust models from Chicago Pneumatics, with a sturdy, red finish, aluminum casing. The housing construction makes this air tool feel solid in hand, and it proved to be quite stable when turned on. The trigger is standard, built in on the side, with a throttle break under it, designed to turn off the pneumatic die grinder when the pressure is off of the handle.
This particular die grinding model is ideal for high-speed polishing and grinding, while the manufacturer also suggests tire scuffing and cleaning to another of its strong suits. The trigger has a speed regulator that reacts to palm pressure, and the exhaust vent is set at the back to prevent blowouts. The air tool can be powered by an averagely sized air compressor, with no need to recharge several times while you work with it.
10. Astro 1221 Die Grinder Kit with Rotary Burr Set
Astro designed this set to fulfill all the needs a craftsman or a machinist could ask from a pneumatic die grinder. With a set like this one, you will be able to cover everything from cutting to cleaning and polishing. It contains a couple of pneumatic die grinding units, one with a 0-degree, and one with a 90-degree angle for burr and drill extensions. Besides the angle difference, both air tools are pretty much the same.
The handles are designed to be composite for a firmer grip, and the trigger on both units is standard, built in on the side. The safety is underneath in the form of a throttle break. Exhaust vents are set on the back to prevent blowouts, and both units weigh about a pound total.
Additionally, Astro put an 8-piece rotary burr set with these two grinders. The set covers the essentials and will help you resolve any standard die problem you stumble upon.
How does a Pneumatic Die Grinder Work?
As with any pneumatic tool, the whole working process of a die grinder starts in the air compressor. A highly-pressurized air stream is made in the compressor and sent through a rubber hose to the die grinder. Once the pressure reaches the grinder’s inlet, it enters the small rotary chamber. Through this chamber, all the pressure energy is transformed into rotary power, which is then exerted via the collet.
If all of this sounds a bit too complex, remember that the drills that dentists use are considered die grinders, though they are incredibly delicate. The collet is essentially an empty slot that holds the burr extension (more about these later) and rotates it very, VERY fast! We are talking about up to 50 thousand rotations per minute or RPM for short. Rotations this high are necessary for the grinder to slice, grind and cut through metal and other materials.
All the excess air is vented through an exhaust opening, which is usually located somewhere on the back of the die grinder. Due to the high RPM speeds and ultra-strong pressurized air traffic, die grinders sometimes tend to heat up during prolonged use. This is why it is essential to take breaks and wait for it to cool off for a bit.
Pneumatic Die Grinder Buying Guide
These spectacular machines have a wide arrange of functionalities and roles within various industries and workshops. From heavy-duty engineering to art. They resemble a version of dentists’ drills and tools. Knowing this, it is time to dive in into the details and see what kind of features you can expect, and how to utilize these tools in the best possible way. Let’s grind into it!
1. Collet Angle
The very first thing anyone will ask you when you say you have a pneumatic die grinder will most certainly be something about the angle. Essentially, pneumatic die grinders can be divided into two major angle groups:
- 90-degree angle die grinders – These are made to help you reach hardly reachable spots and difficult corners, especially on metal constructions. 90-degree die grinders are mostly used by welders and metal workers. However, they are pretty useful in combination with circular polishing extensions.
- 0-degree or linear die grinders – With models like these, the collet is positioned straight after the rotary chamber, linearly. Linear die grinders can be attached to small saws and are great for cutting into hard metals. In contrast to the 90-degree type, this one can be controlled much more easily, especially in the case of smaller models, which brings us to the next topic.
2. Pneumatic Die Grinder Size; How Does It Affect the Performance?
Even though it is intuitive, the logic of “the bigger, the stronger” does not apply in the case of pneumatic die grinders. The vast majority of popular models out there are pretty similar in size, so we call it normal sized. These provide an average RPM in the range of 10 to 20 thousand. A regular model fits in the size of your palm and weighs no more than 3 pounds on average.
But there is something out there popularly called “pen” die grinder. As the name suggests, they are much smaller, and they are linear (0-degree). The reasonable thing to assume would be that pneumatic pen die grinders produce fewer RPMs and are weaker, but an average pen grinder can go as far as 50 to 60 thousand rotations per minute. Yes, you’ve read that right. Fifty thousand RPMs. However, it is important to note that these models are somewhat expensive due to the intricate precision that takes to make them.
3. Burrs and Extensions
This is where it gets interesting. Remember all that versatility we talked about? It is all in the extensions of a die grinder. To make sure that the extension or burr can fit the die grinder you have, check the diameter of the collet. The standard ones are either .125 or .25 of an inch.
The most used burr extensions are usually sold in sets of eight. Some manufacturers include them in the standard package with the tool itself, but to be honest, most of them don’t. This means that you will have to invest some more into a burr set. In these standard sets, you can usually find metal sanders and grinders of different angles and diameters. This should do the trick, especially if you are a beginner.
But grinders tend to shine at one more thing, and that is polishing! Just imagine that kind of ultra-high rotation combined with a fine polishing cloth. The 90-degree grinder models are especially good at polishing because you can apply more pressure to their backside, thus speeding up the process and raising the quality of the shine.
Another great use of high RPMs is sanding. There is a wide variety of sanding extensions, disk and burr ones, that you can insert in the collet. Fine sanding of difficult angels can only be achieved by a pneumatic die grinder. Regular sanders are usually too bulky and unprecise, but a small intricate air tool can reach it without an issue.
With the right burr extension, a really small and pointy one to be exact, you can turn your pneumatic die grinder into an engraving tool. The little, pen-type, die grinders we mentioned are much appreciated by jewelers all over the world.
4. Personal Protective Equipment – your best workshop friend!
Inexperienced people tend to underestimate the kick a pneumatic die grinder can make, usually because of its size. Do not be fooled. These machines are as powerful, if not more than, nail guns and air hammers. They are even more dangerous because of the high-velocity rotary action. You cannot afford to hurt yourself, or your environment, so it would be best to remember pneumatic tools safety tips and wear protective gear at all times. This includes:
- Skin protection – Since you will be cutting and machining a lot of metal, it is best to always have a fire-resistant suit on. Gloves are also a must, due to the heat that is freed from all the air pressure, and due to the fraction between the grinder and the surface you are working on. Sparks can start flying, so it would be best to cover your whole face and neck.
- Respirator or a paper mask – If you are working with metal that tends to fall apart into microscopic particles, protecting your mouth and nose is crucial. Metal microparticles are easily inhaled and can cause a lot of problems along the line.
- Eye protection – same reason as with the skin and respiratory precautions. You need to protect your eyes from all the particles that will be flying around. A standard pair of safety goggles will do the trick.
- Hearing protection – An often-forgotten safety measure. Air compressors are loud on its own, and pneumatic die grinders are not much different. Use earplugs or noise-cancelations headphones to reduce the stress on your ears.
And that’s a wrap! In this guide, you will find all the essential info needed to get to the best pneumatic die grinder to match your requirements. You should take some time and study the guide and the reviews we prepared for you, yes, but there is another thing. Because of the enormous utility of these tools, it would be wise to think about the tasks and jobs you will be performing. Do not try to get everything at once, because that is bound to be a dead end. Take your time and assess your needs and wishes.
We sincerely hope that we manage to shed some light on this complex topic. Pneumatic die grinders are a tool every workshop should have, so why not invest some time and learn about them. If you want to add or ask us something, feel free to do it in the comment section below. Let’s get grinding!