A bench grinder is a standard benchtop type of grinding machine used for a myriad of day to day do-it-yourself tasks. It is essential equipment that you will need to keep your tools in optimal condition. Just like angle grinders and die grinders, bench grinders are handheld, but they offer more control than the other two. Also, they do more than just grinding, and they are easy to use and maintain.
Depending on the type of grinding wheel and grit, bench grinders can be used for sharpening various cutting tools, including chisels, drill bits, and tool bits. They are also used in metal fabrication projects such as shaping metal before fitting or welding. Bench grinders come in different types and sizes. The difference mainly lies in the operating speed and how quickly they can be adjusted.
Types of Bench Grinders
There are four major types of bench grinders for both woodworkers and metal fabricators. These bench grinders differ in size, use, the type of wheel used, and also type of grit. These are;
i. Automotive Bench Grinder
An automotive bench grinder is mainly used for various metal equipment and a whole range of cutting tools. It is quite popular, and it is designed to be extremely stable and balanced, especially if you do a lot of repetitive tasks. Besides, it does not require much adjustment before and after use. It is often used to grind and polish engine parts, door hinges, and much more.
ii. Woodworking Bench Grinder
The woodworking bench grinder is used for sharpening tools and generally smoothing cutting edges. It is also used to grind and sand wood hence the name woodworking. In addition, this grinder runs at a slower speed than other types of grinders allowing you to work with the required degree of precision.
iii. Standard Variable Speed Bench Grinder
Standard variable speed grinder, as the name suggests, allows you to adjust the speed as per your project needs. This means that it can handle pretty everything thrown at it as you can alter the speed to control grinding power. Also, it can accommodate different types of grinding wheels, and because of that, you can use this bench grinder for any job. Besides, this bench grinder allows you to work with the accuracy you need; the lower the speed, the higher the precision.
iv. Portable Bench Grinder
This type of bench grinder is lightweight and easy to move from one working site to another. It is smaller than a full-size bench grinder and easy to adjust from time to time, especially when you need to work somewhere else. Also, it can do most jobs that a bigger model can do, but it is not as powerful when working on harder materials like steel.
Selecting the right bench grinder wheel
The wheel is the component of the grinder that is involved in the actual work. As such, you must choose one that is going to suit your projects. Each wheel is fitted with a grit level, which acts as a mini blade for grinding/sharpening. Also, the wheels have a factory issued rotating speed which, when used with the correct grit, it will enable the bench grinder to sharpen or repair tools quickly. However, the wheels are fragile, but the risk can be minimized if you take precautions and picking the right ones.
- Straight Wheel: The straight wheel is the most popular bench grinder wheel, and it used for any type of surface grinding. The wheel makes a concave shape, making it ideal for sharpening chisel and other similar tools. A straight wheel can also be used for centerless or cylindrical grinding.
- Tapered Wheel: The tapered wheel features a design that narrows towards the edges. This design enables it to get into grooves more and other spaces easily. It is also ideal for more delicate works, including sharpening gear teeth as well as grinding threads.
- Cylinder Wheel: A cylinder wheel will serve as the best option if you need to deviate from a standard horizontal wheel. Cylinder wheels usually are hollow and huge enough to be used both vertically and horizontally. Also, cylinder wheels can go up to about 12 inches to allow you to grind a large piece of metal with reduced downtime.
- Saucer Wheel: You’ll need to invest in a saucer wheel if you deal with a lot of saw blades. A saucer wheel will allow you to sharpen your saw blades efficiently.
- Diamond Wheel: A diamond wheel is designed to work on tough material that requires a considerable amount of grinding power. The edges are lined with diamond bits, and because diamond is one of the hardest substances on earth, this wheel is capable of sharpening just anything.
The Grit types
Aluminum Oxide Grit
Aluminum oxide is a common grit, and it is available in different colors with brown and gray being the most preferred ones. The color of the grit is vital as it affects both the effectiveness and the cost. Brown and gray are low-priced, but they are workhorses. These grits are used on several applications, including grinding high/low carbon steel.
White and pink, on the other hand, have a cooler grinding/cutting action, which is needed to grind harder steel. They are, however, relatively expensive than their brown and gray counterparts. Ruby red grit is used to sharpen the toughest objects, but it is the most costly of all colors.
Silicon Carbide Grit
Silicon carbide grits come in green and black, and they are majorly used for finishing. Black is usually used to sharpen softer objects, including plastics and stones. Green grit, on the other hand, is exceptionally sharp, which makes it perfect for stronger materials such as plasma sprayed metal and titanium.
Ceramic grit is a new entrant and also the most expensive grit. Unlike other types of grits, ceramic grit does not dull as you use it. Instead, this grit fractures and becomes sharper the more it is used. This saves you more money and time as you don’t need to resurface the wheels as often.
By now, you probably made up your mind on which bench grinder will suit your needs. Getting a good one to start with will ensure that you get more use out of your tool, and it will save you beyond tool and time costs. One important thing to keep in mind before choosing a bench grinder is the type of jobs you are involved in. An auto mechanic will definitely need something powerful than a woodworker, and as such, you want to get one that is suited for the job you are doing.
You’ll also need to remember that the wheels and the grit can be the difference great grinding experience and a massive disappointment. However, just like any other tool, how well the bench grinder work will come down to learning how to make the most out of it.