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If you’re trying to choose between these two tools, read this article for an overview. We’ll cover the similarities and differences between die grinders and angle grinders before revealing the major differentiating factor between them. You’ll also get advice on when to use each type of tool, and which is better overall.
What Is a Die Grinder?
A die grinder is a high-speed handheld rotary power tool. Die grinders are often called ‘dremels’, which is a reference to the best-known manufacturer of these types of tools.
The plastic or metal body of the tool contains a motor, which turns a spindle or mandrel at around 10,000 RPM. Bits are connected to the spindle or mandrel to change the capability and function of the die grinder.
Die grinders can be used on metal, wood, plastic, and even glass. They achieve a wide variety of functions, including sanding, honing, polishing, etching, engraving, machining, and of course, grinding.
Die grinders were originally developed for use in tool and die making. To manufacture products, molds, fixtures, jigs, guides, and cutting tools must be precisely created and replicated. Differences as small as a thousandth of an inch can derail the manufacturing process. Die grinders were developed to precisely shape and remove material, especially on the inside of cylinders used as molds.
These versatile tools are available in both electric and pneumatic versions. The electric versions are often referred to simply as ‘rotary tools’, and are best for light-duty jobs, as they can only accept smaller bits. For heavy-duty machining, a pneumatic die grinder is the tool of choice.
Electric die grinders are slightly more versatile than pneumatic versions, as they are also able to accept routing bits.
While cutting discs can be attached to die grinders, allowing them to slice through most materials, they are more commonly fitted with different kinds of bits. One kind of bit used with die grinders is called a burr.
A very coarse carbide burr is used to smooth soft materials such as plastic, aluminum and wood. Other non-ferrous metals can be conditioned with a medium-coarse burr. A fine burr is appropriate for hard and ferrous metals such as iron or steel.
Other attachments and accessories for die grinders include sanding drums, laps, and grinding cones. Sanding drums are rubber cylinders coated in abrasive material, and are used for sanding curved or rounded surfaces. Laps use loose abrasive powder between two pads to achieve an accurate finish. Grinding cones smooth and polish hard to reach areas.
Compare the Dremel 3000 vs 4000 tool.
What Is an Angle Grinder?
An angle grinder is a handheld power tool, primarily used for abrasive material removal. It is designed to be used with discs that attach to a spinning mandrel. Large bearings help the tool handle side-to-side forces generated when the face of the disc is introduced to material. These discs are typically very easy to remove and change out.
When backed by the powerful motor, these discs can perform a variety of jobs. A cutting disc or cut-off disc can chop through almost any material. Rebar, paving stones, tile, cast iron pipes – with the right disc and proper technique, an angle grinder can cut through all of these and more.
Angle grinders can be used to:
- Cut wood
- Cut metal
- Sand wood
- Cut cast iron pipe
- Cut pavers
- Cut bricks
- Cut asphalt
- Grind concrete
- Sharpen mower blades
Diamond tuckpointing discs are often attached to an angle grinder for mortar removal. These discs can quickly and easily remove old mortar without damaging the existing bricks.
For cleaning, stripping, and polishing, wire attachments are used. The wires can be twisted, knotted, or unbound, depending on the material to be removed. A cup-shaped wire brush can be attached for polishing larger areas.
Angle grinders are available in several sizes, and are categorized by the size of disc they can accept.
- A 4″ angle grinder therefore accepts discs that are four inches in diameter. This is the most common size.
- 7″ angle grinders are also fairly common.
- While 9″ angle grinders exist, they carry an increased risk of injury over smaller versions and have even been banned on some work sites.
Die Grinder vs Angle Grinder
Now that you know the basics about these two tools, you’re ready to explore the most important similarities and differences. Understanding how angle grinders and die grinders compare to each other will help you select the right tool for your workshop, as well the right tool for any job.
Both tools have the word ‘grinder’ in the name, but that isn’t the only thing they have in common. Angle grinders and die grinders require similar safety precautions and are versatile tools with overlapping uses.
Both die grinders and angle grinders are rotary tools. This means they function by spinning an attachment of some kind. Other rotary-type tools include drills and routers.
Grinding, or abrasive material removal, is the most common use for either of these tools. They can also both be used for cutting, polishing, sanding, and cleaning.
Die grinders and angle grinders are versatile tools with many functions. Depending on the attachment (disc or bit) that is connected to the grinder, these flexible tools can tackle a wide variety of tasks around the shop.
Both types of grinders rotate at high speeds, meaning any piece of debris could become a projectile. The discs used for grinding are known to shatter, and can cause life-changing facial penetration injuries. Protect your face with a full-face shield mask.
While angle grinders always come with an adjustable guard, die grinders often lack this important safety feature.
Apart from protecting your face, eyes, and neck from projectiles, you should also use hearing protection anytime you use a die or angle grinder. OSHA requires employers to provide ear protection whenever noise levels are above 85 dB for an extended period of time. Angle and die grinders generally operate around 110 dB.
While many jobs can be accomplished by a die grinder or an angle grinder, the two are not completely interchangeable. Differences include the orientation of the attachment, the jobs they can complete, and the size and power of each tool.
Angle grinder discs are attached to the side of the tool. The face of the disc is used for polishing, sharpening, or grinding. The edges of the disc are used for cutting.
Die grinder bits are inserted into the barrel of the tool, in line with the body. The exception to this rule would be right-angle die grinders, which are a specialty tool used to access hard-to-reach places.
Only a die grinder can be used for precision cutting and grinding. Etching and engraving materials such as wood, glass, or metal can also be accomplished with a die grinder, while an angle grinder would be too powerful for this kind of detailed work.
Die grinders are generally smaller than angle grinders. A pneumatic version may weigh as little as 1 lb, and be as small as seven inches in length. Electric versions weigh around 4 lb, and are usually around 15 inches long. They can often be operated using only one hand.
Two hands are needed to safely operate an angle grinder, and these machines usually come with two handles. A four-inch angle grinder might weigh around 5 lb and have a length of 15 or 20 inches. Larger, seven-inch angle grinders can easily weigh in at 15 lb, and could be 20 to 25 inches long.
The smaller size of the die grinder means it can go places the angle grinder can’t, making it useful for awkward cuts in small spaces.
The motor of a die grinder has less than one horsepower. Angle grinder motors are more powerful, between one and five horsepower, depending on the model. Angle grinders are usually electric or battery-powered. Die grinders are usually powered pneumatically, by compressed air.
Compare the angle grinder to the cut off tool for another option.
Major Differentiating Factor
The major differentiating factor between die grinders and angle grinders is precision. Die grinders can be used to manufacture molds, jigs, and gauges with high levels of accuracy, such that the variation from one workpiece to another is less than one thousandth of one inch.
Angle grinders cannot provide the same level of precision. What they can offer is quick material removal, with minimal effort.
When to Use a Die Grinder
Use a die grinder when precision matters more than speed. The best dremel tool on the market will allow you to make very precise cuts, compared to the angle grinder.
Die grinders are easily maneuvered and controlled, making them ideal for detailed work. When a precise cut is necessary, or you can’t risk removing too much material, choose a die grinder.
Die grinders can also be used for etching and engraving glass, metal, or wood.
Compare the most popular Dremel models in our review.
When to Use an Angle Grinder
Use an angle grinder when speed matters more than precision. The best angle grinder is versatile and fast at a variety of cuts.
Cutting through rebar, grinding away mortar, chewing through cast iron pipe – these are jobs that require more power than finesse. Angle grinders, with their greater power, achieve these tasks more quickly than a die grinder.
Which is Better, a Die Grinder or an Angle Grinder?
An angle grinder is better than a die grinder for quickly removing large amounts of material.
A die grinder is better than an angle grinder for making precise cuts, etching, and engraving.