What Is an Angle Grinder?
An angle grinder is a handheld device with a spinning disc used for grinding, cutting, sanding, sharpening, and polishing a wide range of materials. It’s aggressive, fast, and built to tear through tough surfaces like metal, concrete, tile, and more. Whether you’re cleaning up welds, cutting rebar, or grinding mortar, an angle grinder gets the job done quickly.
It’s one of those things that seems like overkill, until you use it. Then it becomes a go-to for dirty, heavy-duty work.
History of the Angle Grinder
Angle grinders date back to the 1950s when Flex—a German company—introduced the first portable version. Early grinders were large and powered by compressed air. Over time, manufacturers like Bosch, Makita, and DeWALT brought compact electric versions to the job site. As discs and motors improved, so did their versatility, turning them into a staple in construction, metalwork, and fabrication shops.
What It’s Used For
Angle grinders are designed for cutting, shaping, smoothing, and removing material. Common uses include:
With the right disc, it’ll handle just about anything you throw at it.
What to Look for When Buying
Not all grinders are equal. Here’s what to focus on:
- Disc Size:
- Most common is 4 1/2 inch—compact, versatile, and good for most tasks
- Larger sizes (7 inch, 9 inch) are heavier and more powerful, ideal for deeper cuts or bigger surface areas
- Power Source:
- Corded: More power and continuous runtime
- Cordless: Great for portability, especially in hard-to-reach places
- Pneumatic: Found in shops or industrial setups, powered by air compressor
- Motor Power:
- Measured in amps or volts
- For corded, look for 7 to 10 amps for general work
- For cordless, go with 18V or 20V systems for enough muscle
- Speed (RPM):
- Higher RPM means faster cutting and grinding
- Variable speed models give more control when switching between materials
- Safety Features:
- Paddle switch or dead-man switch shuts off power if released
- Adjustable or quick-release guard for spark control
- Soft start and overload protection are worth having
- Ergonomics:
- Look for rubber grips, side handles, and solid weight balance
- A grinder that feels awkward will wear you out faster
Pros and Cons
Pros
Cons
Disc Compatibility
Your grinder is only as useful as the disc you put on it. Common types include:
- Cut-off wheels: Thin, used for slicing through metal or bolts
- Grinding wheels: Thicker, for smoothing welds and shaping metal
- Wire wheels: For rust or paint removal
- Flap discs: Great for sanding and smoothing
- Diamond blades: Ideal for cutting tile, concrete, and stone
- Masonry wheels: Used for brick and mortar work
Check the arbor size and RPM rating on the disc to make sure it’s compatible with your grinder.
Safety and Maintenance Tips
Who This Is For
- Homeowners doing heavy DIY projects like tile removal or fence repair
- DIYers cutting metal, resurfacing concrete, or restoring old items
- Pros in welding, fabrication, construction, and auto repair
If you work with metal, concrete, or anything tough, an angle grinder belongs in your setup.
FAQ
Technically yes, but it’s not recommended. It’s risky and can cause kickback. Use a circular saw or oscillating device instead.
Usually because the disc binds, especially when twisting mid-cut. Let the disc do the work and cut in a straight line.
Corded offers more power and runtime. Cordless gives you more flexibility. For long sessions or heavy grinding, corded is the way to go.
Final Thoughts
An angle grinder is loud, dirty, and powerful—but when you need it, there’s no substitute. It cuts through metal, shapes concrete, removes rust, and handles rough jobs quickly. As long as you stay safe and use the right disc, it’s a workhorse you’ll reach for again and again. Don’t let its size fool you—it’s one of the most capable devices in the garage or jobsite.