The Ultimate Guide to Angle Grinders

Angle grinders, also known as disc grinders, are portable power tools that are designed for polishing and grinding. They are used in various fields and industries, including construction, metalworking, and emergency rescue.

Angle grinders come in various varieties in terms of shapes, working, and power sources. An angle grinder may be powered via an electric motor, compressed air, or a petrol engine. If you are looking to invest in an angle grinder, you are reading the right article. In this guide, we will take you through all the essentials that you should know before buying an angle grinder. So, let’s get started.

Types of Angle Grinders

a corded angle grinder from DeWaltCorded Angle Grinders

This type of angle grinder is the most powerful as they take power directly from the AC socket. However, they are heavier and bulkier than other kinds. Also, you need constant access to a power socket to run them. Therefore, if you are looking for a powerhouse of an angle grinder that can perform well with heavy-duty jobs, then you want a corded angle grinder.

a cordless angle grinder from DeWaltCordless Angle Grinders

If your top-most requirement is to get a compact angle grinder, then cordless ones are for you. They are smaller and lighter compared to their corded counterparts. Moreover, they are a tad bit less powerful. The main selling point of this type of angle grinders is its portability as you can easily move it around at remote locations efficiently.

As the battery-powered angle grinders are getting better and better every day, a time will come that people won’t even need a corded one (or the time might have come).

a variable speed angle grinder from MakitaVariable Speed Angle Grinders

As the name suggests, this type of angle grinders’ discs can be set at different speeds so accommodate a wide range of applications. If you want to do high-precision work, then you can set the disc of the variable speed grinder at a high RPM for better performance. Some models also feature paddle switches for enhanced control and convenience.

an air angle grinder from IngersollPneumatic or Air Angle Grinders

When talking about cheap, lightweight, and convenient models, then air or pneumatic angle grinder is the best option. They don’t require electricity or battery to be powered. All you need to do is plug it into your air compressor, and you are good to go. If you already own many pneumatic tools, then choosing an air angle grinder over any other would be an intelligent decision.

a straight angle grinder from DeWaltStraight Angle Grinders

The wheel of a straight angle grinder is set at a 90° angle, enabling you to grind outer edges and inner parts of pieces quite efficiently. The unique type of disc used in these angle grinders is what makes them a better choice over the standard angle grinders (in some instances).

If you want a more powerful and professional angle grinder for your workplace, then check out our article on Top 5 Electric Bench Grinders in 2020.

Different Types of Wheels and Discs

silicon carbide grinding discsSilicon Carbide Grinding Discs

These discs are specially made for the shaping of metals. Silicon grinding discs enable you to efficiently remove the materials without much effort while preventing surface damage.

sanding discsSanding Pads and Discs

If you want to remove old paint for surface preparation, then sanding pads and discs are an excellent choice for this purpose. You can also use them for fine sanding and coarse.

Grinding wheelsGrinding Wheels and Discs

A grinding wheel is made from an abrasive compound that allows you to perform a variety of grinding and abrasion functions quite efficiently. The abrasive grains allow for better cutting and the bond supports and combines the grains during the cutting process

cut-off grinding wheelCut-off Grinding Discs

Cut-off grinding discs are made to cut sturdy items and materials, such as bolts, metal piping, rods, and rebars.

a wire brush wheel from DeWaltWire Brush Wheels

Wire brush wheels enable you to remove paint and rust effectively. They also allow removal of the burrs from rough-cut metal surfaces.

a diamond cutting wheel from LenoxDiamond Cutting Wheels and Discs

These particular type of wheels and discs is suitable for cutting concrete, granite, masonry, and tile. You can also opt for diamond blades, which are great for both dry and wet cutting.

flap discsFlap Discs and Wheels

Flap discs and wheels work similarly to the wire brush, but they are equipped with flaps instead of wires. This produces an effective combination of weld beads with the metal you are working on.

aluminum oxide grinding wheels from PowertecAluminum Oxide Grinding Wheels

These are oxide-based wheels that are highly recommended for a wide range of applications, including woodworking, cutting crumby materials, and more.

Factors to Consider Before Buying an Angle Grinder

Power Source

As already discussed above, there are various types of power sources when it comes to running an angle grinder – for example, cordless, pneumatic, corded, variable speed, etc. You should choose one according to your budget, requirements, and feasibility.

Disc Size

Larger discs are used to perform high volume work, and they produce a smooth finish in half the time. On the other hand, a small compact disc is used where precision and sharpness is required. Therefore, opt for this type of disc if you want to focus on tasks or jobs that require high precision work.

4-9 inches of disk size is quite standard to get started with.

Disc Speed (RPM)

The faster the speed (RPM), the more it produces the desired results. An average angle grinder can have revolutions per minute, ranging from 5,000 to 10,000. Therefore, for quality results, go for the one that offers higher RPM value.

The RPM value of an angle grinder also depends on its power rating. Stronger the motor, higher the disc speed.

Type of Grinders

When searching for an angle grinder, you will come across a variety as they come in various styles (as already mentioned above). You can go for the type that aligns well with your requirements and budget. For example, if you want to carry your angle grinder around, then go for the cordless one. On the other hand, if you want a more powerful angle grinder that can work quite effectively on the most robust surfaces, then there is no match for a corded angle grinder.


Size is also one of the most important factors to consider before purchasing an angle grinder. If you want to do larger jobs, then the bigger angle grinders would be perfect for you. The size of a grinder isn’t determined by its overall length only, but also its disc’s size.

If you want more high precision work, then you can go for small angle grinders that can spin at a faster speed, hence giving more power to cut and polish the metal.


Choose a grinder that you are comfortable to work with for an extended time. Grinders come in different weights – some are lightweight while others can be quite heavy to hold. A perfect grinder is not too lightweight nor too light to handle.

Motor Power

The voltage, watts, and amperes vary among every model. People prefer buying a grinder or any power tool that comes with a power ranging from 110 volts to 220 volts, and the wattage rating from 500 to 2500 watts.

The higher the power rating (watts), the higher the performance of the machine will be. However, it might get a bit heavier due to a larger motor equipped inside. If you are looking for an angle grinder for use in household projects, then you will be perfectly fine with the one having a lower rating. On the other hand, professionals can opt for heavy-duty angle grinders that are suitable for handling different types of projects with ease.


As with any power tool, safety is quite an important factor to consider in an angle grinder. You don’t want to invest in a tool that might hurt you. Grinders have more risk of injuries compared to other power tools. Therefore, you need to consider the safety precautions in it before purchasing.

You can look for safety features like an eye shield that will help prevent the debris from getting into your eyes.


The stronger your grip on the tool is, the better performance you will achieve. Hence, better results. Therefore, always look for a comfortable handle, preferably with an ergonomic grip. It would be great if you can get your hands on an angle grinder that is equipped with an adjustable side handle. This will help make the machine easier to use for both left and right-handed people.

You can also check if the grinder has an anti-vibration handle, which will make the machine much more comfortable to use for an extended period of time. Hence, it will also help in reducing fatigue.

Safety Procedures

Following are some safety procedures that you should follow when using an angle grinder:

  • Keep the safety guard on the grinder at all times.
  • Make sure to unplug the grinder while switching wheels before changing discs.
  • Use both hands for the safe operation of the grinder.
  • Ensure that the grinder is off before plugging it into a power supply.
  • Always opt for the appropriate type of spinning disc for the task.
  • Use the angle grinder according to the instructions provided in the user manual.
  • Maintain complete focus and take regular breaks to avoid injuries and fatigue.
  • Inspect the grinder before use and replace faulty parts as necessary (if any).
  • Always wear safety gear like face shield/safety glass, work gloves, and proper clothing that can prevent debris and withstand sparks.
  • Run the grinder for some time before using it to ensure that there are no defects in its operation.
  • Don’t forget to secure your workpiece and keep flammable objects away from the sparks while operating the grinder.
  • Purchase a grinder that comes with easy interchangeable discs.

Final Words

Angle grinders are one of the most powerful tools that can be used for various projects. We hope this article has helped in clearing all your confusions regarding an angle grinder and provided you with insightful information on them.

And yes, don’t forget to follow the safety precautions once you get your hands on an angle grinder.