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How to Choose and Use a Bench Grinder

Love making sparks fly? So do we. If you're here for romantic advice, you're in the wrong place; if you're here to quench your thirst for knowledge, read on.

Bench grinders are some of the handiest tools you can have at your disposal. From grinding to reshaping to sharpening, they're workhorses when it comes to caring for and repairing metal implements of all kinds. Sharpening knives, chisels, lawnmower blades, axes, scissors, and more is a breeze with one of these helpful machines in your garage or shop. Here, your friends at WEN have put together some helpful pointers on how to choose and use a bench grinder. 

Types of grinders

Grinders are usually broken down into two types: wet/dry sharpeners or grinders, and standard bench grinders and buffers. 

Wet/dry sharpeners

Wet/dry sharpeners are usually used for sharpening tools that don't need a lot of heavy corrective work. They incorporate an onboard water storage tank to cool a fine-grit abrasive stone, and many often include a leather stropping wheel for final honing and burr removal. 

WEN BG4270T 10-Inch Two-Direction Water Cooled Wet/Dry Sharpening System

The WEN BG4270T 10-Inch wet/dry sharpening system is a quiet, precise, all-in-one sharpening center.

Wet/dry sharpeners are great for sharpening kitchen knives, woodworking chisels, scissors, and axes to a razor-sharp finish. They usually run at a slow speed and use a very fine-grit wheel, meaning they don't take off much material at a time, but offer superior control. 

Standard bench grinders, polishers, and buffers

These are the bench grinders you may have seen in your high school shop class, and are the type of grinders we'll be focusing on for the rest of this article. They usually consist of a central motor housing, a sturdy cast-iron or cast-aluminum base, and grinding or buffing wheels on each side of the motor housing.

WEN BG4282 being used to grind a wood chisel

The WEN BG4282 bench grinder being used to sharpen a wood chisel.

Bench grinders usually incorporate a series of tool rests, as well as wheel guards and eye guards, to offer better control and help guard against sparks and flying debris. They usually come with aluminum-oxide or other abrasive grinding wheels, and are used for heavy material correction and removal. Usually, they include a low-grit (often 30 - 40 grit) and a medium-grit (often 60 - 80 grit) wheel. Replacement wheels and other accessories, such as wire wheels, are readily available.

Buffers and polishers usually eschew guards and tool rests in favor of an open design, which offers excellent access to their woven-fabric wheels. These machines are great for finishing, buffing, and polishing metals, plastics, and some woods, and usually require their wheels to be charged with buffing compound before use.

How to choose a bench grinder

When choosing a bench grinder, make sure to take a few factors into consideration.


Bench grinders are usually measured by the diameter of their wheels. For example, a 6-inch bench grinder uses 6-inch-diameter wheels; an 8-inch bench grinder uses 8-inch-diameter wheels.

Generally speaking, 8-inch bench grinders are larger, heavier, and often both more expensive and more powerful than their 6-inch counterparts. They usually offer more working area and a stronger motor, and are best suited for heavy-duty or professional jobs. 

6-inch grinders are versatile, compact, portable machines that are great for most general-purpose tasks around the house, but they may not hold up to the demands of a production environment. However, they're usually less expensive than their 8-inch cousins, and take up very little room on your workbench. 


Bench grinders' motors are measured in amps - the amount of current they're rated to handle in operation. Generally, more amperage equates to more power to handle heavy-duty grinding tasks.

Choose a bench grinder with an induction motor - they run cooler, quieter, and much longer than other motor types.


Most bench grinders run between 3450 - 3600 RPM, but slow-speed models are also available. These units offer maximum precision and control, and because they run at a slower speed (usually around 1725 - 1800 RPM), they tend to cause less heat buildup in the workpiece being sharpened. This helps with longer edge retention and longer life for cutting implements. 

WEN BG4286 3-Amp 8-Inch Slow Speed Bench Grinder

The WEN BG4286 3-amp 8-inch slow speed bench grinder runs at 1725 RPM, offering maximum control and minimum heat buildup.

Variable-speed models, such as the WEN BG4280 and BG625V, are also available. These models use electronic controls to precisely dial in the motor speed so that it's perfectly tuned for the task at hand. However, this precision and versatility means that a variable-speed model will usually command a higher price than an equivalent single-speed model.

WEN BG625V being used to sharpen a lawnmower blade

The WEN BG625V 6-inch variable-speed bench grinder is great for sharpening lawnmower blades, knives, chisels, scissors, and more.

Extra features

Other features to keep an eye out for include: 

  • Adjustable eye guards and spark deflectors. As the grinding wheel wears down, adjustable spark deflectors and eye guards help you stay safe and get the most life out of your grinding wheels.
  • Integrated drill bit guides built into the tool rests, or available as separate attachments. These make sharpening drill bits much easier than trying to freehand it.
  • Angle-adjustable tool rests. Different tools require different cutting angles; adjustable tool rests make this much easier.
  • Onboard worklights. These help you see what you're doing even when hunched over the grinder.
  • Onboard quenching trays. As alluded to above, when grinding, heat buildup is the enemy. These trays hold water or oil to help keep your workpiece cool.
  • Cast-iron bases and mounting holes. At the very least, your grinder should be bolted to its mounting surface to prevent it from wandering around, but a heavy cast-iron base will help further stabilize it and reduce vibration.

How to use a bench grinder

Always make sure to read your owner's manual completely and follow its instructions. Below are some general tips. 

  1. Take proper safety precautions. Wear personal protective equipment - ANSI Z87.1-approved safety glasses, ear protection, respiratory protection, etc. Do not wear gloves, ties, jewelry, or loose clothing, and make sure to tie back long hair. Keep other people and animals away from the grinder.
  2. Stand to the side of the tool. It helps prevent the sparks created (and there will be plenty!) from landing on your clothes. 
  3. Bolt the bench grinder down securely, whether to a workbench or bench grinder stand.
  4. Use pliers or clamps to hold small workpieces.
  5. Choose the correct grinding wheel for your application. Coarse (low-grit) grinding wheels will remove material faster but cause more heat buildup and leave a lower-quality finish. Fine (high-grit) wheels will remove material more slowly, but leave a better edge. Wire wheels are great for removing buildup, smoothing welds, deburring, and removing rust.
  6. After turning the bench grinder on, let it reach full speed before trying to sharpen anything.
  7. Keep control of your workpiece. Hold it securely against the grinding wheel, letting the tool do the work. Move the workpiece slowly back and forth to keep an even grind. 
  8. Only grind on the face of the grinding wheel. Never grind on the side of the wheel.
  9. Keep the workpiece cool. If you don't have a quenching tray, or the workpiece is too big to fit in a quenching tray, give it a break from time to time. 

One other tip - if you're sharpening an existing edge, consider marking it with a permanent marker. That way, while keeping a consistent angle, you can see which parts have already been ground and which have not - marked sections will need more attention.


Thanks for reading! We hope this has been a helpful guide on your journey to choosing a bench grinder. If you have any questions about WEN bench grinders or wet/dry sharpeners, or need help deciding which one is right for you, please give us a call at 1-847-429-9263 (M – F, 8 – 5 CST), or drop us a message here to talk to our friendly and knowledgeable technical support team. 

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