If you use metal tools regularly, the bench grinder provides one of the cheapest ways to get the best out of your tools by keeping their edges sharp and rust-free. Depending on the work you do, the grinder is a multi-purpose tool you can adapt for a wide range of applications.
Bench grinders are valuable tools every professional metal worker and serious DIYer should invest in and know how to use. The tool is ideal for polishing, grinding, cutting and more. Plus, it’s affordable compared to the work it does.
In this article, we provide the fundamental details about the bench grinder, what it does and how to use it safely. This guide will help you appreciate the tool and the value it can provide your workshop.
What Is a Bench Grinder?
A bench grinder is a two-wheeled work bench tool that is a constant feature in metal shops and wood workshops. It is a versatile tool ideal for a wide range of applications in metalwork, woodworking, shoemaking, construction and more.
While there are large bench grinders, most people use the small-sized models powered with one-quarter to 0.5 horsepower motors rotating at 3000 t0 3600 revolutions per minute. To use the bench grinder, all you need do is fix it securely to the workbench or a similar mount.
Parts of the Bench Grinder
The bench grinder has the following important parts:
- Wheels (Coarse wheel and fine wheel)
- Eye shield
- Wheel guard
- Tool Rest
- Spark deflector
- The Wheels
The bench grinder has a two-wheel setup you can use to sharpen tools and equipment, polish metal, and many other applications. One wheel has a fine texture while the other has a coarse texture. Each of the wheels is on either side of the motor compartment.
The work the wheel does depends on the number of grits. Delicate jobs require the gentle impact of 80 or 100-grit wheels while coarse 36 to 60-grit wheels are perfect for heavy-duty sharpening tasks.
The motor drives the wheels on the bench grinder. Most grinders designed for homeowner and general workshop use come with small motors with less than 2 horsepower. However, heavy-duty bench grinders used for industrial applications can have motors that produce over 40 horsepower.
- Eye Shield
This part is located on the upper part of the bench grinder. It is a safety feature that improves motor control and prevents wheel fragmentation.
- Wheel Guard
Every bench guard has a wheel guard which holds the wheel in place to prevent cracking and fragmentation. The wheel guard is a vital part for the protection and smooth operation of the bench grinder and it covers about 80 percent of the wheel. However, improper mounting of the guard can cause damage to the wheel and reduce the tool’s efficiency.
- Tool Rest
The tool rest is affixed to the wheel guard in front of the wheel. It provides a hard, smooth and balanced surface to place materials you want to work on the bench grinder. This allows you to work with consistency, reduce accidents and improve your results.
- Spark Deflector
This feature deflects sparks away from your body during operation of the bench grinder. It is often fixed to the top of wheel guard to catch sparks and debris as they come off the workpiece. The spark deflector is made of a durable material and it’s advisable to engage it whenever you use the tool.
The parts of a bench grinder make sure you achieve consistent and professional results while ensuring safe operations. Whether you are cutting or shining tools or constructing materials, the coarse and fine wheels are more than capable of any task you throw at them. However, make sure you know the proper and safe operating procedures.
Bench Grinder Use
If you know how to use one, a bench grinder is an excellent tool in the hands of DIYers and tradesmen. Despite its simplicity, you can’t beat the repetitive force of this tool when you need to remove rust or polish materials. If you are looking to buy a grinder, check out this bench grinder buying guide for affordable options.
Here are some things you can do with a bench grinder.
- Sharpen Metal Tools
Before electricity and powered tools, people sharpened blades and tools with stones. Nowadays, the fine wheel of the bench grinder does a better and faster sharpening job. The grinder gently blends the edge of dull tools in minutes, making them as sharp as new and with less effort.
The bench grinder helps you get the best out of your tools, garden equipment and other such materials. From your chisels, spades, hoes, lawnmower blades, knives, to screwdrivers, the grinder will renew the cutting edge of your tools and save you the cost of replacing them every time.
So long as you set the tool to the right rotating speed and position the object at the right angle, the grinder will do the rest.
- Remove Rust from Tools
A bench grinder is also an excellent machine for removing rust from tools. Whether you forgot your tools outside or stored them in a damp location, rust can reduce the longevity of metal objects, make them dull and untidy. Get the shine back with the bench grinder.
To remove rust with a bench grinder, you need to mount a wire wheel on the spindle and set the machine at a slower speed. This ensures you don’t scrape excess material from the tool since most rust is superficial. Once you remove the rust, store your tools properly in a cool and dry location or apply grease if you can’t control the damp.
- Shape Materials
One of the major operations a bench grinder serves in metal and wood workshops is shaping materials. Whether you have an oversized workpiece that needs delicate resizing or create a certain shape on a table leg or metal workpiece, the coarse wheel can get the job done.
Apart from metal and woodworkers, contractors in the construction industry, jewelers and even shoe makers use the grinder to bring creative designs to life. With enough creativity, you can use the bench grinder to shape different materials in the metal shop, wood workshop, at home and even in automotive shops.
But make sure the wheel can handle the material.
- Clean and Polish
With a buffing wheel, the bench grinder is an ideal tool for cleaning and polishing metals, wood and other materials. Unlike the coarse or fine wheel, the buffing wheel is covered with a soft cloth that cleans or polishes anything you place against it. However, the fast movement of the wheel creates tremendous amounts of friction and heat, increasing the risk of overheating.
When using the bench grinder to polish a workpiece, it’s advisable to have water close by. Avoid placing the workpiece for too long on the grinder and dip it in water to reduce overheating. This is even more important if you are polishing wood as the high temperature can burn it.
Like the angle grinder, the bench grinder can also serve as a deburring tool. However, you need a stiff buffing wheel to debur materials with this tool. Metal shops often need to remove sharp projections and edges on welded metal for improved consistency and the bench grinder is a fast and efficient way of completing this task.
So when you need to smooth welded joints or remove imperfections on your workpiece, mount a quality buffing wheel on your bench grinder and get to work.
How Does a Bench Grinder Work?
The bench grinder works on a simple principle like the sharpening stones of old. There are a wide variety of wheels for grinders based on the work you want to do. These wheels have abrasive materials called grits which are stone-like structures.
A bench grinder has a motor and a spindle on which you mount wheels of different abrasive levels. The grit is the abrasive particle that grinds away tiny pieces of the workpiece. Used grits become dull and give way to newer, sharper grits which continue to cut away bits from the material being ground.
You can control the speed of the bench grinder to meet the job requirement. If you want to sharpen tools, use the finer tools and a slow motor speed to achieve the ideal results. With heavy-duty tasks such as shaping and deburring, coarse wheels are the preferred choice.
It is important to adhere to safety precautions when using a bench grinder. The tool can be noisy and the wheel can shatter if an object falls on it during operation. It’s advisable to test the integrity of the wheels periodically.
To do a wheel test, hold the wheel with your finger in the mounting hole at the center. Hit the wheel midway between your hand and the outside edge with a screwdriver. The wheel is OK is you hear a ring but if you hear a thud, get a replacement.
Never attempt to use a broken wheel as it can shatter anytime and cause serious injury to you and damage the machine.
How to Use a Bench Grinder
The bench grinder is not a notorious tool but anything that rotates at 3000 rpm needs a good understanding of the operating procedure for safety reasons. Before you use a grinder, make sure you have the following available:
- Well-mounted bench grinder: It’s important to have a top quality bench grinder mounted properly.
- Wheels: You also need to have the right wheels such as grinder wheels or buffing wheels.
- Working Tool Rest: The tool rest is an important feature of the bench grinder if you want to work in safety and get excellent results. If your unit has an inferior tool rest, get a better aftermarket alternative.
- Dipping Water: Using a grinder causes a lot of heat which can damage the wheel and the workpiece. Have a bucket or a pot of water close by to keep things cool and safe.
- Space: Besides the table space, make sure you have enough wiggle space to work freely with the grinder. You don’t want metal tools stuck between the wheel guard and the wheel.
- Safety Equipment: To protect your arms and eyes from debris and sparks, wear long-sleeved shirts, gloves and face masks. You may also need to wear hearing protection if your unit is a noisemaker. If possible, wear steel-toed shoes to protect your toes.
- Accessories: You can improve your productivity and comfort with simple accessories such as wedges designed to help position different tools and workpiece perfectly on the grinder. It’s possible to create most of these wooden wedges too.
- Check Your Grinder
Once you have all the above supplies, check that your bench grinder is in good condition. Make sure the wheels are mounted correctly and not catching the wheel guard.
Ensure the tool is secured firmly to the bench to prevent vibrations that could cause inconsistent grinding operations. Also, make sure the tool rest works correctly and check the spark deflector is engaged.
- Prepare Your Work Area
Clear your work area of debris and objects you don’t need. Create enough space to handle the workpiece and have your dipping water near you to control overheating. Now is the time to wear your safety equipment before you power your grinder.
- Power the Bench Grinder and Grind Away
Power the grinder and wait until it reaches maximum speed before introducing the workpiece. When it has reached the desired speed, hold the workpiece tightly with both hands and place it gently against the grinder wheel.
Make sure the workpiece only touches the face of the wheel, not the sides to avoid damage. Placing the workpiece on the sides can cause cracks and even shatter the wheel.
If you are shaping wood, hold the area of the material against the grinder slightly for short periods with a back-and-forth motion. Depending on the task, you can adjust the grinder’s speed to either fast or slow setting.
For sharpening tools, place the object on the tool rest while holding firmly with both hands. Then push the tool’s blade to the grinder at an angle to the blade’s bevel. Avoid overheating and dip the tool in water if it becomes too hot.
The bench grinder is a simple tool that can perform several functions in most workshops. Whether you are a welder, a woodworker or a DIY enthusiast, the grinder offers a plethora uses for many professionals.
With the right wheel and experience, you can use a bench grinder to sharpen tools and objects, polish materials, clean surfaces, debur imperfections and shape work pieces. You only need to have a powerful enough unit and know how to use it safely and correctly.
There is a wide range of bench grinder models on the market and most are affordable. You might not see reason to buy one of these tools now, but it is a worthy investment that can help skyrocket the value and longevity of your tools and garden equipment.
We hope this article has shed more light on the bench grinder and its functions. The next step is to learn how to use one to get the best out of the tool when you add it to your workshop.