Best Pneumatic Die Grinders
A Complete Guide for Buying the Best Pneumatic Die Grinder for your Needs! Latest 2022 Models
When your project requires sanding, shaping, polishing, or cutting, a Pneumatic Die Grinder may be the best tool for the job. However, not all die grinders are the same! These versatile power tools are indispensable for mechanics, machinists, fabricators, wood carvers, and hobbyists. They are available in different configurations and sizes with specific features for a multitude of applications.
Consequently, some of the die grinders currently available are made from cheap components and won’t hold up to a harsh workshop environment.
Why Listen to My Advise?
My familiarity with Pneumatic die grinders spans over 40 years of having used those provided by the machine shops where I was employed and my own. Of course, a lot of things have changed over that period of time although the basics remain the same.
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Before making a hasty purchase that may result in lost time and frustration, there are multiple issues you should consider before selecting the best die grinder for your shop.
Although there actually three types of die grinders including Pneumatic, Electric and Cordless this guide will focus exclusively on Compressed Air Powered models.
Pneumatic Die Grinders
Originally Die Grinders were designed to operate from compressed air which is a common utility in any machine shop. The motors are basically an air turbine that can generate spindle speeds up
to 56,000 rpm’s. A pneumatic die grinder can produce enough torque to drive a carbide bur or large diameter abrasive cut-off wheel.
Pros
Because of the weight/power ratio and ergonomics Pneumatic die grinders are generally better than that of an electric die grinder.
These attributes make an air-powered die grinder well suited for use in machine shops, welding shops, and auto repair and restoration shops. These types of businesses typically have a commercial size air compressor to supply the necessary volume of air. Additionally, pneumatic die grinders are significantly less expensive than an electric powered model.
Cons
One of the down sides to pneumatic powered die grinders is they are designed to be operated at full-throttle. Although it is possible to regulate the speed by adjusting the air pressure at the inline regulator, it also cuts the grinder’s power.
These pneumatic power tools tend to be very noisy requiring ample hearing protection while operating. Additionally, it’s not just the noise produced from the tool; a pneumatic die grinder uses a large volume of compressed air and will drain the receiver of a medium or moderately large air compressor quickly. This of course causes the compressor to cycle off and on in an effort to keep up with demand. Because of this issue, pneumatic die grinders are generally not the best option for a small home workshop.
Another issue to consider before purchasing a pneumatic die grinder is that some models require frequent lubrication to prevent the air motor bearings from seizing up. That’s why it’s vitally important to have an Air Pressure Regulator/Lubricator installed inline between the compressor and the air grinder.
Consequently, this brings up another issue with operating a compressed air powered die grinder. As the grinder runs the compressed air is exhausted to the rear of the tool which tends to refrigerate the back of your hand. Additionally, a small but noticeable amount of oil will begin to accumulate on your hand with models that have a rear exhaust port.
Top 8 Pneumatic Die Grinder RECOMMENDATIONS
NOTE: To help narrow down the best Pneumatic Grinder for your needs, visit our Quick Shop Side-by-Side COMPARISON TABLE first. Or SCROLL down to view Recommendations and complete details of each unit
#1 Chicago Pneumatic CP860 and CP860ES Heavy Duty Air Die Grinders
Features:
- HP Rating: .54
- Configuration: Straight or Extended Anvil
- Free Speed RPM’s: 24,000
- Free Speed Consumption: 21 CFM
- Collet Size: 1/4″
- Air Inlet Size NPT in: 1/4″
- Minimum Hose Size: 3/8″
- Dimensions: Straight 4.02 x 2.99 x 7.99 inches, Extended Anvil 13.5 x 3 x 2.7 inches
- Variable Speed: Yes, built-in air regulator
- Included: (2) Collet Wrenches
- Warranty: 2 Years
Overview
Company
Chicago Pneumatic is an American corporation founded in 1901 with worldwide distribution. Their pneumatic power tools are esteemed as some of the best in the industry.
The Chicago Pneumatic CP860 and CP860ES Heavy Duty are professional grade die grinders. Each CP tool is built in Japan with high quality Japanese parts that are designed to last long after other cheaply made die grinders fail.
Non-Slip Collet
Chicago Pneumatic has outfitted the CP860 and CP860ES with a 1/4″ Collet that will hold any 1/4″ dia. Die Grinder Bit or Burr securely.
One of the most common complaints attributed to air grinders is that the bits and burrs tend to slip in the collet. The collet design used on the CP Series grips tighter without having to risk over tightening it. Each grinder includes (2) nice quality collet wrenches.
Ergonomics
The Square design may not look comfortable to hold but it actually feels natural in your hand and won’t slip or turn while your using it.
Speed and Power
These air-powered grinders develop a whopping .54 hp (400W) and are very energy efficient, consuming only 21 CFM of compressed air. The rated speed is 24,000 rpm’s while not under load (free speed).
A highly beneficial feature you won’t find on most other pneumatic die grinders is a Built-in Air Regulator that automatically adjusts to match the work you are doing.
The grinder is activated with a Lock-off Throttle to help prevent hand fatigue.
Lubrication
Like any other pneumatic die grinder the CP860 and CP860ES requires lubrication to prevent motor and bearing failure. Chicago Pneumatic specifies using an inline Air Pressure Regulator/Lubricator with SAE #10 Air Tool Oil such as the Ingersoll Rand 10P Edge Series. Keep in mind a little bit of oil goes a long way.
WARNING: It is common practice to inject a few drops of oil in the hose port of a pneumatic power tool prior each use. This is taking a big risk of ruining your die grinder if you happen to forget. Always use a proper in-line lubricating system that feeds a steady regulated flow of oil to protect your tool from seizing.
Connections and Air Pressure
The CP860 and CP860ES have 1/4″ NPT (National Pipe Thread) air inlets. A 3/8″ dia. hose is recommended to deliver the necessary air volume at 90 PSI and average 10 CFM. (Refer to the Instruction Manual for Air Supply Requirements)
My Recommendation
The Chicago Pneumatic CP860 and CP860ES die grinders are designed for extended usage in machine shops and other industrial applications. They are well suited for grinding clearance and relief on dies or venting an injection mold. These are invaluable tools for general maintenance in auto repair and restoration shops such as porting, general high-speed polishing, cutting, and paint and gasket removal.
If you want to equip your shop with a highly dependable and long-lasting power tool, the Chicago Pneumatic CP860 Straight or the CP860ES Extended Anvil are two of the very best pneumatic air grinders available.
#2 Ingersoll Rand Air Grinder Edge Series 3101G or 3107G
Features:
- HP Rating: 1/3
- Configuration: Straight and Right Angle
- Free Speed RPM’s: 27,000
- Free Speed Consumption: 18 CFM
- Collet Size: 1/4″ dia
- Air Size NPT in: 1/4
- Minimum Hose Size: 3/8
- Dimensions: Straight 6.6″ x 2.8″, RA 6.6″ x 3.2″
- Variable Speed: No
- Included: Grinder, (2) Wrenches
- Warranty: 1 Year
Overview
Company
Ingersoll Rand has been around for over a century and is widely known and respected across multiple industries for manufacturing quality Industrial tools. Their air compressors are found in many machine shops and manufacturing facilities because of their advanced engineering and dependability
The Ingersoll Rand Air Heavy Duty Die Grinder Edge Series is designed for use in machine, welding, fab, millwright, and auto repair shops. These high quality die grinders are made to last and withstand rugged use in harsh environments.
..rugged but easy to operate!
Although it’s a heavy duty grinder it is lightweight at about 1 pound. The ergonomic grip makes it comfortable to hold and helps prevent fatigue during long work sessions.
Spindle Speed and Power
The 1/3- horsepower motor is powerful enough to drive large diameter carbide burrs or handle a cut-off wheel in sheet metal. Stainless Steel ball-bearings insure long life even at the higher free speed of 27,000 rpm’s. The Air Edge Series are equipped with a Self-Locking Throttle that enables you to articulate the tool without cutting the power.
Variable Speed
Ingersoll Rand lists this model as a “Variable Speed” grinder. And although it is true you can regulate the spindle rpm’s by manipulating the throttle arm it is somewhat difficult to hold in a set position.
Like most pneumatic die grinders, this model is designed to work best at full-throttle. Another option for regulating the speed is by adjusting the air pressure down or up at the inline regulator. Just keep in mind that when you cut the pressure below 90 psi the power also decreases.
The Air Edge Series are outfitted with a ¼” collet that will securely accommodate a wide variety of bits and burrs for just about any application. A set of collet wrenches are included.
The Ingersoll Rand Air Edge Series 3101G is the Straight configuration and the 3107G is the Right Angle configuration.
Check Out this Cool Customer Review VIDEO!
Lubrication
One of the features that you will appreciate about the Ingersoll Rand Air Edge Series is the way it is lubricated. Lubrication is provided via a grease fitting located at the top. You will need a small grease gun such as the Astro Pneumatic Tool 101. The advantage of this design is it eliminates the need for an inline lubricator like other pneumatic grinders so you don’t end up with your hand covered with oil. Additionally, it gives you the freedom to use any available compressor with or without a lubricator. This feature makes the Air Edge Series a good choice for commercial service professionals.
The Ingersoll Rand Air Edge Series are general purpose air grinders that are ideal for de-burring sharp edges, finishing, polishing, porting, cutting, and light weld grinding.
If you are a tradesman and demand top quality tools the Ingersoll Rand Air Grinder Edge Series 3101G or 3107G two of the best available. Both models are backed by a 1 year manufacture’s warranty.
#3 SUNTECH Series Pneumatic Die Grinders
Overview
Company
SUNMATCH is one of the best manufactures of air powered tools you probably never heard of! If you are looking for a moderately priced pneumatic die grinder you will be delighted with any one of the fine quality SUNTECH Series offered by Sunmatch.
SUNMATCH is a family-owned business established by 3 brothers in 1985. Headquartered in Taiwan, they have developed a very impressive array of air-powered tools that have become widely accepted in multiple industries.
Consequently, these are not cheaply made imports like so many of the other die grinders that have flooded the market. SUNMATCH has combined innovative features with industrial grade components that perform well and keep on working.
Versatile Uses
These quality power tools are the perfect addition to any shop for on-the-spot metal removal, grinding, polishing, and cutting. The Noise-Reducing feature will be greatly appreciated by any other worker who happens to be in the same room.
A 1/4″ Collet will accept any 1/4″ shank burr, bit, or grinding and polishing attachment. A set of collet wrenches is included.
SUNMATCH offers (4) Pneumatic Air Grinder configurations that includes STRAIGHT, 90° Degree, 115° Degree, and EXTENDED ANVIL.
User-Friendly Features
Each model (with the exception of the SM-53-5530 Industrial Straight) includes an Over-molded Composite Grip that helps prevent slipping and operator fatigue. Additionally, a Safety Throttle Lever that locks into position when activated prevents accidental cut-off’s while operating. Your ears will appreciate a Rear Exhaust Silencer that dampens the noise level to only 84db compared to 100+ for other pneumatic die grinders.
SUNTECH SM-5E-5300 Extended Anvil Air Grinder
Features:
- HP Rating: .3 hp
- Configuration: Extended
- Free Speed RPM’s: 25,000
- Free Speed Consumption: 4 CFM
- Collet Size: 1/4″
- Air Size NPT in: 1/4″
- Minimum Hose Size: 3/8″
- Dimensions: 9.54 x 6.77 x 1.79 inches
- Variable Speed: No
- Included: (2) Collet Wrenches
- Additional Features: Over-molded Composite Grip, Safety Throttle Lever, Rear Exhaust w/ Silencer
- Warranty: 1 Year
The SUNTECH SM-5E-5300 is ideal for reaching into those tight, hard-to-access places. This air-powered tool is built for rugged use and is an excellent option for auto repair or machine shop applications.
SUNTECH SM-55-5300 115° Air-Powered Grinder
Features:
- HP Rating: .3 hp
- Configuration: 115°
- Free Speed RPM’s: 25,000
- Free Speed Consumption: 4 CFM
- Collet Size: 1/4″
- Air Size NPT in: 1/4″
- Minimum Hose Size: 3/8″
- Dimensions: 9.54 x 6.77 x 1.79 inches
- Variable Speed: Yes
- Included: (2) Collet Wrenches
- Additional Features: Over-molded Composite Grip, Safety Throttle Lever, Rear Exhaust w/ Silencer
- Warranty: 1 Year
Sometimes a grinding job can only be reached from an angle that a Straight or 90° grinder just won’t work. The SUNTECH SM-55-5300 115° Pneumatic Die Grinder is the perfect choice for those special applications.
This tool is very use full in machining, auto repair and restoration, welding, fab, mill right, and home workshops. The Noise-Reducing feature will be appreciated by any other worker in the same room.
SUNTECH SM-52-5300 90° Pneumatic Die Grinder
Features:
- HP Rating: .3 hp
- Configuration: 90°
- Free Speed RPM’s: 25,000
- Free Speed Consumption: 4 CFM
- Collet Size: 1/4″
- Air Size NPT in: 1/4″
- Minimum Hose Size: 3/8″
- Dimensions: 9.54 x 6.77 x 1.79 inches
- Variable Speed: Yes
- Included: (2) Collet Wrenches
- Additional Features: Over-molded Composite Grip, Safety Throttle Lever, Rear Exhaust w/ Silencer
- Warranty: 1 Year
In conclusion, 90° Air Grinders are the best option for polishing and sanding operations. They are a must-have tool for automobile repair and restoration tasks such as removing pain with a brush attachment or an old gasket. Accordingly, 90 degree pneumatic grinders are also necessary tools in the fabrication trade. Additionally, they are also commonly used for polishing out tool marks on molds in the tooling trade.
Like the other SUNTECH models, the SM-52-5300 90° Pneumatic Die Grinder is a tool that will get the job done and keep on working long after a cheap budget brand gets tossed in the trash can.
SUNTECH SM-53-5530SU Industrial Die Grinder, Straight
Features:
- HP Rating: .5 hp
- Configuration: Straight
- Free Speed RPM’s: 32,000
- Free Speed Consumption: 5.7 CFM
- Collet Size: 1/4″
- Air Size NPT in: 1/4″
- Minimum Hose Size: 3/8″
- Dimensions: 9.37 x 5.53 x 1.89 inches
- Variable Speed: Yes
- Included: (2) Collet Wrenches
- Additional Features: Steel Motor Housing, Safety Throttle Lever, Forward Exhaust Ports
- Warranty: 1 Year
By every definition, the SUNTECH SM-53-5530SU is an Industrial-Grade air grinder. It is designed for the most demanding applications with the ability to endure the harshest conditions. The rugged air motor develops .5 HP at free speed and generates a screaming 32,000 rpm’s.
Unlike its cousins, this straight pneumatic air grinder is built with a steel motor housing instead of the more comfortable. This feature makes the SM-53-5530 especially suited to withstand rough handling. It can easily survive drops and bumps without damage.
Another notable difference is the positioning of the Exhaust Ports: instead of locating them to the rear of the unit, they are set in front of the grip area which all but eliminates any oily residue from the exhaust. Unfortunately, it does not have the noise-reducing device like its cousins listed above
If you are shopping for a pneumatic die grinder for serious industrial use the SUNTECH SM-53-5530SU is one of the best available.
Top 8 Pneumatic Die Grinders Comparison Table
| Product | Main Features | Recommended For | Read Complete Details |
|---|---|---|---|
 Chicago Pneumatic CP860 Heavy Duty Air Die Grinder | Price: $ HP: .54 RPM’s: 24,000 Dimensions: 4.02 x 2.99 x 7.99 inches Weight: 1.25 Warranty: 2 Year | Industrial and production environment usage. Utilizes all 1/4" attachments. General purpose grinding or cutting steel, wood or plastics |  |
 Chicago Pneumatic CP860ES Heavy Duty Extended Anvil Die Grinder | Price: $ HP: .54 RPM’s: 24,000 Dimensions: 4.02 x 2.99 x 7.99 inches Weight: 2.1 Warranty: 2 Year | Industrial environment for cutting, grinding, polishing w/ 1/4" attachments | |
 Ingersoll Rand Air Grinder Edge Series 3101G | Price: $ HP: 1/3 RPM’s: 27,000 Dimensions: 6.6″ x 2.8″ Weight: 1 lb Warranty: 1 Year | Gen. purpose industrial/commercial use for metal, wood, plastics removal. 1/4" burrs, grinding, cutting, polishing attachments. | |
 Ingersoll Rand Air Grinder Edge Series 3107G 90 Degree | Price: $ HP: 1/3 RPM’s: 27,000 Dimensions: 6.6″ x 3.2″ Weight: 1.3 lb Warranty: 1 Year | Gen. purpose applications industrial/commercial environment. Use for sanding, grinding, polishing w/ 1/4" bits and attachments | |
 SUNTECH SM-5E-5300 Extended Anvil Air Grinder | Price: $ HP: 1/3 RPM’s: 25,000 Dimensions: 9.54 x 6.77 x 1.79 inches Weight: 1.5 lb Warranty: 1 Year | Industrial environment usage where noise is an issue. | |
 SUNTECH SM-55-5300 115° Air-Powered Die Grinder | Price: $ HP: 1/3 RPM’s: 25,000 Dimensions: 9.37 x 5.53 x 1.88 inches Weight: 1.1 lb Warranty: 1 Year | Industrial environment usage where noise is an issue. | |
 SUNTECH SM-52-5300 90° Pneumatic Die Grinder | Price: $ HP: 1/3 RPM’s: 25,000 Dimensions: 7.73 x 3.77 x 2.04 inches Weight: 1.1 lb Warranty: 1 Year | Industrial environment usage where noise is an issue. Use for cutting, grinding, polishing w/ 1/4" attachments | |
 SUNTECH SM-53-5530SU Industrial Die Grinder, Straight | Price: $ HP: 1/2 RPM’s: 32,000 Dimensions: 9.37 x 5.53 x 1.89 inches Weight: 2.44 Warranty: 1 Year | Heavy duty industrial production environment. Remove metal, wood, or plastics w/ 1/4" carbide burrs, bits, and attachments | |
What Exactly is A Die Grinder?
As the name implies, these versatile power tools were originally developed for use in the metalworking industry. They were specifically designed to facilitate Tool & Die Makers to be able to make adjustments and alterations on dies without dissembling them.
These special purpose hand grinders operate at very high speeds from as low as 15,000 rpm’s up to as high as 55,000 rpm’s. They are constructed with collets to accept a variety of bits that include carbide burrs in multiple configurations, cut-off discs, brushes, polishing, and abrasive bits.
What Is a Die?
Over the course of my career when people ask me – what do you do for a living, I tell them I’m a tool & die maker. That reply almost always prompts a puzzled look or an ahh, as though they are familiar with the trade. But, in my experience that is seldom the case and to avoid embarrassment that’s when the subject usually gets changed.
Most people associate the term “die” with the process of passing from life to death. Or, in another spelling it denotes a substance that imparts color to an object or material. However in this instance the term refers to a custom-built tool made from steel that’s designed to cut or form metal in industrial manufacturing processes. These unique tools are built by highly skilled craftsman called Tool & Die Makers using machine tools such as milling machines, lathes, surface and cylindrical grinders, plus a wide variety of hand tools.
Some examples of parts made with a DIE would be the hood, trunk, fenders, oil pan, and valve covers of your car. Another familiar example would be an aluminum or steel pan used for baking bread.
After the tedious process of building the die has been completed, it is mounted in a punch press for testing. If every component is correctly designed, machined, and fitted precisely the die can then be put to use for mass producing the parts it was designed to make. On the other hand, if there is a problem such as a clearance or relief issue a die grinder can be used to resolve the problem without having to remove the die from the press.
A Highly Versatile Tool!
Because of their versatility, die grinders have become widely used in other industries besides metal working. They are highly useful for auto repair and restoration shops, welding, fabricating, electrical, gunsmithing, and home workshops.
Electric Die Grinders
Since electricity is a more user-friendly utility than compressed air it has become the preferred power source for die grinders. It’s decidedly easier to manage a power cord than an air hose when trying to perform work. An electric die grinder typically produces spindle speeds of from 15,000 to 25,000 rpm’s making them suitable for running small to medium size bits and carbide burrs. However they do not generate as much torque as a Pneumatic die grinder which could be an issue if your goal is to shape, cut, or remove large amounts of material.
Because of the size of the motor electric die grinders tend to be heavier and bulkier than an air-powered grinders. This could present an issue for accessing tight, difficult to access places.
A huge benefit of electric die grinders is they are much quieter than their noisy pneumatic cousins. Instead, they are equipped with permanently lubed and sealed bearings so there is no need to lubricate them. Consequently, there is no oily exhaust to deal with. Additionally, electrical outlets are much more available than a compressed air source.
Perhaps the more significant consideration is that electric die grinders are generally more expensive than the alternative.