Tool School: Cut, Grind, and Polish with the Versatile Angle Grinder

You won’t find a more versatile or unforgiving tool than the angle grinder. They’re loud and dangerous, but indispensable for jobs that can’t be done any other way.

Angle grinders work by spinning a small disc or wheel at a high rate of speed (from 8,000 to 11,000 RPM) to cut, grind, or polish. They are available as corded, cordless, or pneumatic (air powered), and can be purchased for as little as $29 for the popular Porter-Cable to $345 for a cordless Milwaukee.

Angle grinders are categorized by disc/wheel size and amperage. Disc sizes can range from 4, 4.5, 5, 6, 7, 9, and 12 inches, but for most DIYers the 4-4.5 inch range will suffice. At that size, you’ll be able to perform most general tasks and have a wide range of discs and wheels to choose from. An angle grinder in the 5-9 amp range will provide more than enough power for your cutting and grinding needs, and unless mobility is a top concern, stick to a corded model for the best value.

An apartment dweller may not find much use for an angle grinder. But if you’ve got a workshop and do any welding or light construction projects around your home, an angle grinder should be part of your arsenal. Here are the most common tasks that an angle grinder can accomplish.

Metal Cutting & Grinding

A metal cutoff wheel uses aluminum oxide as an abrasive to cut rebar, rusted bolts, and iron fencing. The smaller discs run less than $3 each and can be purchased for as cheap as 10 for $8 from Harbor Freight. A metal grinding wheel is necessary to clean up welds.

Metal Cleaning

Wire wheels and brushes are extremely effective for removing rust and paint from metal. They are available in a variety of shapes for stripping, cleaning, or deburring metal. They are also great for cleaning garden tools of dirt and dried cement.

Tile, Stone, and Concrete Cutting

An angle grinder equipped with a dry cut diamond wheel, can cut ceramic and masonry with ease. They work best for trimming tile or working in tight spots, as well as cutting in for outlets or plumbing fixtures.

Restoring Metal Edges

Shovels, hoes, and lawnmower blades, can be sharpened with an angle grinder fitted with agrinding wheel. You don’t need these tools to be sharp like a knife blade, you just need the edges restored to their original shape.

Grinding Mortar

The first step in tuckpointing brick is clearing out the old mortar. The best tool for that job is an angle grinder with a diamond tuckpointing wheel.

Polishing Aluminum

A polishing wheel or buffing pad will bring aluminum back to it’s shiny self. If the aluminum is really marked up you can start with a high grit grinding disc then move the the polishing wheel.

Remember: safety first! Always wear eye protection when using an angle grinder. Sparks, metal, abrasive debris, and stone are always thrown from the tool. Hearing protection is also recommended as is a face shield for some applications. For masonry work, always wear a dust mask.