Power Tool Buying Guide for Grinders


A grinder is a very versatile tool that can grind, shape, polish and cut through metal and concrete. 

Type of Grinders

Bench GrinderBench Grinder – As the name implies, a bench grinder is designed to be mounted on your workbench.  A bench grinder usually has two wheels.


Stright GrinderDie Grinder or Straight Grinder – A die grinder looks and works like a rotary tool, much like the Dremel.  These tools have a straight shaft.


Right Angle GrinderRight Angle Grinder – This is the most common type of grinder and has a wide range of uses.  As the name implies, the grinding wheel is at a right angle to the shaft of the tool.


Types of Grinder Power

Grinder can be powered by three distinctive options

  • Pneumatic – Air
  • Corded – 110V
  • Cordless – Powered by a rechargeable battery

Grinder Terms

Wheel Size – The wheel size indicated what size the wheel can be used with the tool.  Usually, you will see a wheel size between 4″ and 9″.

Amps – With a corded grinder, this has a correlation to the power of the tool.  The higher the amps, the more powerful the grinder is and the less it will bog down under heavy use.

RPM – This is the speed of the wheel or how fast the wheel will spin.  RPM is rotations per minute.  So an RPM of 4,000 would mean the grinder is fast and will spin about 4,000 times per minute.

Switch – There are two main types of switches, paddle switch, and thumb switch.  A paddle switch run alongside the tool and you the user needs to depress the paddle switch in order to operate the tool.  A thumb switch is a simple switch that a user turns to the on/off position.

Some of the grinders will have variable speed, depending on which brand you buy.  If you are using a variable speed, low speeds are better for polishing, while higher speeds are better for grinding and cutting.


Grinding Wheels

There are many types of grinding wheels on the market.  Make sure you have the right wheel for the job you are performing.


Cut off wheel – Cuts metals such as rebar. 




Grinding Wheel – Cutting Metal, Wood, Shaping or Sharpening hand tools, blades, bits or cutters.  Cut off wheels and grinding wheel look the same from a top view.  A cut off wheel is much thinner.



Diamond Wheel –  Cuts concrete, block, and stone




 Wire Brush – This is used to remove rust and some polishing