Angle grinders and “Dremels” or rotary tools are power tools used mainly for cutting but also for sanding, polishing, and more. Both angle grinders and rotary tools work on glass, wood, and metal, and both offer a variety of wheel attachments according to the job at hand. 

An angle grinder is a larger power tool weighing up to 12 lbs. while a rotary tool is a small power tool weighing closer to 1 lb. 

An angle grinder is more powerful, though its wheel turns slower, and you can cover more area in a shorter time with it. A rotary tool turns at as many as 3 times the RPMs as an angle grinder but with much less HP; however, a rotary tool can do detailing that an angle grinder just cannot do.

Ideally, you want both tools in your shop, the angle grinder for heavy-duty jobs and a Dremel (rotary tool) for light jobs and detailing, but if you can only pick one, that will depend on the job at hand.

 

Angle Grinder

Rotary Tool (Dremel)

Die Grinder

Size

Medium to large power tool using wheels from 4 ½-9” weighing approximately 3-12 lbs

Small power tool using wheels from 15/16-1 ½” weighing from less than 0.5 lb to just under 1.25 lbs

Small to medium power tool using wheels from 2-4” weighing approximately 1-5 lbs

Speed

2,000-11,000 revolutions per minute (RPM)

5,000-35,000 RPM

2,500-30,000 RPM

Power Source

Electricity or air pressure (corded)

Battery or gasoline (cordless)

Electricity (corded)

Battery (cordless)

Electricity or air pressure (corded)

Battery (cordless)

Power

Less than 1 horsepower (HP) to almost 5.5 HP

or

20-volt rechargeable

Less than 1 HP

or

4.8 to 12-volt rechargeable

Less than 1 HP

or

18 to 20-volt rechargeable

Complexity of Use

Two-handed operation

One-handed use

One or two-handed operation

Precision and Versatility

Grinding metal

Sharpening, cutting, sanding, chamfering, deburring, and polishing

Removes mortar, rust, and paint; cleans and polishes metal; and does basic woodworking (not for fine details)

Works on welded joints, metal blades, masonry, sheet metal, rebar, stone, tile, concrete, and more

Perfect for etching, engraving, and carving

Also for sanding, grinding, cutting, polishing, and drilling

Works best on wood, metal, and glass

Grinding, sharpening, chamfering, deburring, polishing, and removing rust

Works best on metal, wood, steel, weld spots…

Attachments

Grinding, wire, metal cutoff, dry-cut diamond, and diamond tuckpointing discs, and wire cup brushes

Flex shaft, circle cutter with straight-edge guide, multi-purpose cutting guide, lawn mower and garden tool sharpener, shaping platform, shield, and 50 accessories, such as a grinder, mini-sander, polisher, and grinding, sharpening, engraving, and carving accessories

Wire, sanding, and polishing wheels, wood-cutting and metal-cutting wheels, grinding and grindstone bits, and carbide burr

Price

$25-$300

Rotary tool

$15-$60

$150 for saw kit

Genuine Dremel

$45-$140

$230 for saw kit

$20-$250

Are you all set to learn the similarities and differences between angle grinders and rotary tools (Dremels)? Well, let’s get to it.

What is an Angle Grinder?

An angle grinder is a power tool with a rotating disc that’s used mainly for grinding and polishing. Designed for two-handed operation, the angle grinder was named so due to the design, which features a cutting head that sits at an angle relative to the drive shaft.

Mae using angle grinder
Consider the material you will be working with, when purchasing an Angle Grinder

When purchasing an angle grinder, consider the material you are going to work with before choosing a particular model. You will need a different size and power if you are removing paint and rust than if you are cutting bathroom tiles or concrete; for most jobs, 7 amps spinning at around 8,000 RPM is a gracious plenty.

While some angle grinders support cutting wheels up to 9″, the one most commonly used is the 4 1/2″ wheel. The angle grinder’s cutting attachments come in an array of choices according to what project you need to complete, like wire cup brushes, and metal cutoff, grinding, wire, dry-cut diamond, and diamond tuckpointing discs.

What is a (Dremel) Rotary Tool?

First, understand that “a Dremel” is a rotary tool. Rotary tools are small power tools, while Dremel is the brand name of a line of tools. Dremel makes rotary tools, saws, oscillating multi-tools, 3D printers, specialty tools, attachments, and accessories; there’s even a Dremel catalog, but you can also get Dremel and other brands of rotary toolsets on Amazon and at home improvement, woodworking, and some other stores.

Rotary tool
Rotary tool and Die grinders are not the same.

Another fact you need to know is that rotary tools and die grinders are not the same things. Die grinders are small power tools, similar to rotary tools, but generally weighing up to five times more; a die grinder is like a cross between an angle grinder and a rotary tool.

A rotary tool is a one-handed handheld mini-power tool. It is a rotating motor joined to a spindle to which you can attach any one of a vast array of available tool bits, such as those for cutting, sanding, polishing, and more; the motor in a rotary tool rotates at a very high rate of speed.

These tools must spin at high speeds to achieve the results of some jobs rotary tools specialize in. For most jobs, a rotary tool needs to spin at roughly 20,000 RPM, but for the really tough jobs, you may need a heavy-duty rotary tool that can spin at 35,000 RPM.

A rotary tool has a simple design with its spindle, the spinning part, connected to its motor; its spindle is threaded to work with the collet and collet nut which work together to hold everything in place and clamp down the flanges. What separates one rotary tool from the next is the amount of torque it can deliver.

Which tool is best for which job?

While an angle grinder and a rotary tool can be used for some of the same purposes on some scale, they are, on another scale, very different tools. You will want to consider the job at hand before deciding which of these two tools you should invest in. Let’s look at why by considering a few different tasks.

Glass Working

An angle grinder is a rough-running tool, so it is not ideal for glass-cutting; however, while not ideal, an angle grinder can be used to cut and round off some types of glass, like glass tiles. This is done using a diamond blade, usually accompanied by moisture for reducing debris, to cut through the glass.

A rotary tool, on the other hand, allows you to cut, sand, and polish glass and etch, carve, and engrave into glass surfaces. Just as with angle grinders, you can’t use a regular blade to cut glass but must use a diamond blade, plus, moisture helps to control the glass dust.

Both tools work on glass, but the first can handle very thick large pieces of glass while the other one can’t, and the other can handle detailed work like etching, carving, and engraving while the first can’t. 

Woodworking

So, an angle grinder is great for woodworking, for doing jobs like edge sanding, rough shaping, stock removal, and sharpening chisels and planer knives. It’s a very speedy method for sanding a new deck or for stripping paint from the outer walls of a building. 

A rotary tool is also a great tool for woodworking. With a rotary tool, you can cut, drill into, and sand wood, shape it, and carve into it with extraordinary precision. Also, a rotary tool may be used to do most of the woodworking jobs of an angle grinder, though it may take forever, but an angle grinder cannot do the detailed woodworking that a rotary tool can.

Both an angle grinder and a rotary tool are good for sanding, shaping, and sharpening, but on two different scales. The angle grinder is large and uses large discs, so it is not good for sanding or shaping small areas or sharpening small blades.

Metalworking

Angle grinders can handle metal, grinding it, cutting it, chamfering, deburring, polishing, and sharpening it; as a matter of fact, this is the primary job of an angle grinder. With one, you can even remove rust; angle grinders work on metal blades, sheet metal, welded joints, rebar, and more. 

A rotary tool also works well on metal, as well; with it, you can grind metal edges, sharpen blades, remove rust, do metal-carving, etching, and engraving, polish and clean metal, and perform fine cuts on hard metals, such as steel.

Both tools work well on many hard metals, but angle grinders are the choice for heavy-duty jobs like cutting rebar that will wear out the motor on a rotary tool. Rotary tools, on the other hand, can do things that angle grinders can’t, like etching and engraving.

Working With Plastics

An angle grinder will work to cut plastics such as IBC and PVC pipes. There is a problem, though. The plastics get hot and melt from the friction, and this clogs the blade.

You can use a rotary tool on plastics, as well, and you can purchase wheels for a rotary tool that are dedicated to cutting plastics. Since plastics do melt from friction, however, it is recommended that you not exceed a speed of 15,000 RPM when cutting plastics.

Angle grinders are not ideal for cutting plastics, but rotary tools, with the right wheels, can handle several plastics, such as plexiglass and vinyl, and cut them the right way without damaging the tool.

Which tool do you need?

Do you see a pattern here? It’s basically angle grinders for bigger jobs and Dremels (rotary tools) for smaller jobs. If you’re like most of us, you would like to have both tools in your shop, but that isn’t everyone. If you only want the right tool for the job, then consider the following.

Choose an angle grinder if you need:

  • A tool for large surfaces (car polishing, rust removal…)
  • A tool for cutting hard materials (tiles, rebar…)
  • A tool for heavy-duty grinding, deburring, and chamfering
  • A tool for essentially larger, heavy-duty jobs

Choose a rotary tool if you need:

  • A tool for stone carving
  • A tool for any type of etching, engraving, and carving
  • A tool for any type of detailing, especially in tiny areas
  • A tool you may want to use for other small jobs in the future (there are cutting, grinding, sanding, and polishing attachments and more in all shapes and sizes for rotary tools)
  • Note: Dremel brand rotary tools are more expensive than other brands.

You could also investigate a die grinder as an option, as it is a somewhat comparable tool. See our chart at the top of the page. Thank you for your time! Probe the exciting articles below.