What is a Bench Grinder?
A bench grinder is a power tool that is present in almost every workshop, and it is used to sharpen other tools that you need for woodworking or other jobs. It consists of a rotating arm with an abrasive wheel attached to it. There are different types of wheels for different purposes, such as grinding, shaping, sharpening, cutting, etc.
Due to its versatility and ability to deliver quick results, a bench grinder is a handy device for every person who works with different tools and equipment. This is why it is found everywhere from workshops to garages. The stationary grinder is fixed on top of a bench or work table, so that it doesn’t move around due to the vibration of the motor.
Why is a Bench Grinder Important?
One of the main reasons why you need a grinder and can benefit from having it is the versatility that it provides. As mentioned above, a table grinder has a wheel attached to it, which is spun by a high-powered motor at a great speed. You can use the spinning wheel to grind, polish, shape, or sharpen any of your tools or workpieces and use them in your projects.
Another reason why you should have a table grinder in your workshop is that it allows you to achieve a level of fineness and perfection that you wouldn’t be able to achieve by hand. Plus, the grinder is easier to control and you can alter the degree of grinding by moving the tool or workpiece back and forth on the wheel.
Moreover, a grinder is suitable for workmen in different professions, such as metal fabrication, woodworking, welding, fitting, manufacturing, and many others.
How to Use a Bench Grinder?
Even if you are new to using a stationary grinder, you can master the skill with a little practice. To use it properly, you need steady hands and precision, otherwise you will end up sharpening your tools the wrong way or making uneven or oddly shaped workpieces. Before you start a grinder, remember to wear the proper work gear, such as gloves and safety goggles.
Also, you need to know the type of wheel you need to add for the job. Wheels vary in levels of coarseness and this makes them suitable for various applications. Once you have determined which wheel you need, you can turn on the machine and wait for it to rotate at its maximum speed.
Next, grab the item or object you need to grind and bring it in contact with the spinning wheel. Make sure to keep it at an acute angle to the wheel, i.e. 25° or 30°. Also, don’t bring the object or push it too close to the wheel at first. Slowly move it towards the wheel, so that you don’t end up overdoing it.
There are some tips that would help you use the grinder properly. Firstly, if you are grinding metal, it tends to get very hot in the process, and this heat can damage the object or tool. Therefore, you should have a bowl or pot of water handy, so that you can stop grinding frequently and dip the tool into water.
Moreover, if you are working with small objects, hold it with pliers so that your fingers don’t get dangerously close to the spinning wheel. Handling small objects while wearing work gloves is also difficult, so pliers will help you achieve a better grip.
Lastly, when sharpening the blunt edge of a tool, there will be sparks flying downwards. When the tool gets sharp enough, the sparks will go upwards, so make sure to keep an eye out for this.
Things to Consider Before Buying a Bench Grinder
When you have numerous options to choose from, it is best to evaluate each grinder using a certain set of factors, which you can read about below.
Size
The size of the table grinder has a direct impact on the type and magnitude of jobs that you will be able to perform. Small stationary grinders are built for low-intensity grinding, sharpening or shaping metal. On the other hand, larger grinders are more suited towards grinding, cutting, or sharpening larger objects and tools.
Make sure to take a look at the size of the power grinder, and also read its detailed description to find out what jobs it is suitable for.
Motor
The motor inside the grinder is one of its crucial components, and it affects the performance of the device. If you choose an option with a larger motor, it would be able to spin larger wheels at higher speeds, thus making it suitable for a variety of jobs and tasks. For heavy-duty jobs, you can make do with a 1 HP motor. For low-intensity projects, you can make use of a ½ or ¾ HP motor.
Speed
The motor doesn’t only provide power to the table grinder, but it also contributes towards its speed. Basically, the higher the horsepower of the motor, the faster it will be able to run. Higher speeds are more suitable for grinding and working with tougher objects. For such items and tools, you need a speed of at least 3000 RPM, whereas softer objects can be worked on using a 1500 RPM motor as well.
Grinding Wheel
The grinding wheel is another important part of the desktop grinder, and different types of wheels vary in their levels of coarseness. For grinding and sharpening tougher materials, you will need a coarser wheel but for softer materials, you can make do with a less coarse grinding wheel. So, you need to choose the right type of wheel for your projects.
Another factor involved with grinding wheels is grit, which determines how smooth or rough you can make the object or tool you are grinding. Grinding wheels are available in two sizes: 6-inch and 8-inch. The former is used for grinding and sharpening at higher speeds, but 6-inch wheels have to be replaced from time to time. On the other hand, 8-inch wheels are suitable for professional projects.
Safety Features
When choosing a grinder, also consider the availability of safety features in it, such as spark deflectors, eyeshields, dust exhaust, cooling system, etc. These features will help you use the tool safely, and they will also ensure that the grinder keeps operating at an optimal temperature and doesn’t break down due to overheating.
FAQs
Q: Can bench grinders be dangerous?
A: Since tabletop grinders rotate a grinding wheel at very high speeds, it can injure your hands if you aren’t careful, especially if you aren’t wearing work gloves.
Q: Do I need to secure the bench grinder with bolts?
A: It is always wise to bolt down the machine onto a workbench or table, because it tends to vibrate strongly when the grinding wheel is turning at a high speed.
Q: Why does my bench grinder have two wheels?
A: Nearly all grinders have two wheels, one of which has a lighter grit and can be used to grind and sharpen softer materials.