What Size Cut Off Wheel Do I Need for My Grinder?
Use the wheel diameter printed on your grinder's nameplate or guard. For most handheld angle grinders that is 4-1/2 inches, with a 7/8 inch arbor hole. The brand matters less than the size marking, so DEWALT, Milwaukee and Makita grinders all follow the same rule.
DEWALT DW8062B5Best overall
EZARC 80711502Thinnest listed wheel
VOISEN 100 Pack Cut Off Wheels 4 1/2 inchClear RPM rating, big packStart with the grinder, not the brand
Cut off wheels are sized to the grinder, and the brand name on the tool does not change that. A Milwaukee, DeWalt or Makita angle grinder of a given size takes the same wheel size as any other grinder of that size.
Look at the nameplate on the grinder body, or at the guard. Most grinders state the maximum wheel diameter they accept, along with the no-load speed in RPM. Your manual lists the same numbers. If you can't find either, measure the existing wheel across its full width.
Many cordless and corded models are sold in a 4-1/2 inch size, which is why that wheel is so common. Larger angle grinders exist, and they take larger wheels and need a matching guard.
Common grinder types and wheel sizes
Use this table as a starting point, then confirm against your own nameplate. The sizes below are typical diameters, not a promise that every model fits every wheel.
| Tool | Typical wheel diameter | What to check |
|---|---|---|
| Small angle grinder | 4-1/2 in | Guard size, 7/8 in arbor, RPM rating |
| Mid-size angle grinder | 5 in to 6 in | Guard rating and nameplate max diameter |
| Large angle grinder | 7 in to 9 in | Guard, side handle, wheel max RPM |
| Die grinder | 2 in to 3 in | Arbor or mandrel size, wheel RPM rating |
| Chop saw or stationary saw | 12 in to 20 in | Not interchangeable with angle grinder wheels |
What size for DeWalt, Milwaukee and Makita grinders
If you own a 4-1/2 inch model from any of these makers, shop for 4-1/2 inch wheels with a 7/8 inch arbor. That is the size most of the products on our best cut off wheels page use. DEWALT's 4-1/2 in 5-pack and 10-pack, the VOISEN 100-pack and the Diablo disc all list a 4-1/2 inch diameter and a 7/8 inch arbor.
If your grinder is a different size, find the number on the nameplate. A 5 or 6 inch grinder needs a wheel that size, and you should not put a 4-1/2 inch wheel on it. A smaller wheel can sit too far from the guard and leave the guard unable to protect you properly.
Never mount a wheel larger than the one your guard is rated for. A bigger wheel will not fit under the guard correctly, and the grinder may be running too fast for it.
What about die grinders?
A die grinder is a different tool from an angle grinder. It is smaller and uses a small-diameter wheel, usually in the 2 to 3 inch range, mounted on a mandrel or arbor. The wheel must match the arbor size of your die grinder, and it must be rated for the tool's speed.
Die grinders often spin much faster than angle grinders. Our page lists a 3 inch wheel rated at 20300 RPM, which is the highest rating on the page and is meant for smaller grinders. Do not use a 4-1/2 inch angle grinder wheel on a die grinder. The speed ratings are built for different tools.
Check these four specs before you buy
Once you know the diameter, confirm the details that decide whether a wheel is safe and useful on your tool.
- Arbor size: the center hole must fit your grinder's spindle. Most 4-1/2 inch wheels on our page list a 7/8 inch arbor.
- Max RPM: the wheel's rating must be equal to or higher than your grinder's no-load speed. Only 14 of 24 products on our page list it, and listed values run from 11000 to 20300 RPM.
- Thickness: thinner wheels cut faster and remove less metal. Listed thicknesses on our page run from 1 mm to 1.2 mm. The Diablo disc lists 1.02 mm and the DEWALT 5-pack lists 1.14 mm.
- Wheel type: bonded abrasive wheels wear down and often use fiberglass reinforcement. Diamond wheels have a solid steel body and keep their diameter.
Bonded or diamond: does it change the size?
Both types come in the same diameters, so the size rule stays the same. The difference is how they wear. A bonded wheel shrinks as you cut, so you replace it. A diamond wheel keeps its diameter, so makers pack fewer of them.
The EZARC diamond wheel lists a 1 mm thickness in 4-1/2 inch size and comes as a pack of 2. The ONEGOTOOL diamond wheel is also 4-1/2 inch and comes as three. Their cut life numbers are maker claims, not verified results, so treat them as a rough guide.
If you cut a lot of metal, compare pack counts against how fast you go through wheels. Our page lists packs from 2 wheels up to 200, and bonded wheels need the larger packs for steady work.
Safety before you mount the wheel
Cut off wheels can break and throw fragments. A few habits lower the risk.
Unplug a corded grinder or remove the battery before you change a wheel. Keep the guard in place and facing you. Wear eye protection, a face shield, hearing protection and gloves, and clamp the work down so it cannot move.
Inspect each wheel before use. Do not use one that is cracked, chipped or damaged. Use a cut off wheel only for cutting, and never for side grinding, because the thin body is not made to take sideways force.
Frequently asked questions
Can I use a smaller wheel on my grinder to save material?
Not safely as a habit. The guard and speed rating are built around the size on the nameplate, and a smaller wheel changes how the guard covers it. Stick with the stated size.
Does a thinner wheel fit the same grinder?
Yes. Thickness does not change the diameter or arbor fit. A thinner wheel cuts faster and removes less metal, but check that the wheel is rated for your tool's speed.
What if my wheel does not list max RPM?
Look at the label on the wheel or the packaging, or contact the maker. If you cannot confirm a rating at or above your grinder's no-load speed, choose a wheel that publishes it.
Can one wheel cut metal and tile?
Some diamond wheels do. The ONEGOTOOL 4-1/2 inch diamond wheel lists metal, tile and stone. A bonded metal wheel should only be used on the materials it lists.