Use a grinding wheel or a flap disc by holding the grinder at a 15- to 30-degree angle relative to the material you are grinding. When cutting, hold the grinder vertically relative to the surface.

When you are cutting through material, instead of holding the grinder at a 15- to 30-degree angle, rotate it so that the disc is at a 90-degree angle to the target surface.

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.

The least common sizes are the 100 mm and 230 mm grinders, or models EAG75100-G and EAG2023RG, respectively. EAG75100-G has a maximum disc capacity of 100 mm or 4 inches and a 16 mm inner diameter.

Sometimes called disc grinders or side grinders, angle grinders range in size from 4.5-inch models for common jobs, such as cutting through metal rods or grinding through tile, to 9-inch grinders ...