Angle Grinders 101: An Educational Guide 

 January 7, 2020

By  Axel Kloch

Having an angle grinder is a complex tool to have. When used correctly, it enhances the efficiency and results of your projects with no issue. That's why we are going to teach you everything you need to know about angle grinders.

When shopping, you need to know how to make the correct decision. Let this quick article tell you how angle grinders work, and different manufacturers to choose from when you're out shopping. By the end of this post, you'll have enough knowledge and information to look for the best angle grinder suited for you.

What Is An Angle Grinder?

As its name suggests, an angle grinder is designed to cut through stone and metal at various angles. Angle grinders are powered by multiple sources such as compressed air, electric motors, or petrol engine.

But, you need to be very careful when using this powerful tool to reduce the chance of injury. Neglectful actions can lead to a cut hand or even more severe effects. Protective clothing is mandatory when working with an angle grinder.


Angle grinders are a valued tool because it's versatile functions and capability to handle cutting tasks. It can be used for polishing surfaces, grinding, and cutting. Because of this, you can use it for virtually anything.

While every angle grinder makes (Porter Cable, Dewalt, Bosch, Makita, etc.), advertises, and sells their model of an angle grinder, in reality, they have similar main features. But, the differences are apparent when it comes to the motor power and the overall design tool of the motor.

Angle Grinder Uses

In essence, your angle grinders are used for a lot of different purposes. Here are some of the main reasons metal workers use them:

  • Cutting bars, rods, steel sheets, screws, or rusted bolts.
  • Sharpening blades such as shears, axes, shears, and mower blades.
  • Making plunge cuts on tiles if the user needs to chop a selection out of the slab tile's center.
  • Used for shaping materials and objects.
  • Cleans out debris and rust from multiple metal surfaces (gates, fences, trowel surfaces, trowels, car parts).

What Different Type Of Grinders

Your grinder's type and build quality are one of the most important things to remember when getting your first angle grinder. Here is a table showing the types of sizes of angle grinders that are available.

Grinder Disc Size (cm)

Grinder Size (in)


4 1/2 inches


5 inches


6 inches


7 inches


9 inches

The most commonly used disc for standard DIY needs is the 115 mm discs. You're going to want to get a pair of discs at this size regardless of any project that you're planning to complete.

When cutting large pipes and doing industrial projects, the 230 mm machines are more useful. These machines are the same as the smaller 115 mm discs but operate on a large scale. They should have the same benefits and features as their smaller body parts.

Because of their weight and size, larger grinders and discs take more skill to use correctly. They provide a lower level of torque and sometimes operates slower than smaller angle grinders.

Now that we know about air grinders let's talk about the different types of power.

Corded And Cordless Angle Grinder

Corded angle grinders are more durable and tend to last longer than their cordless counterparts. A good corded angle grinder is capable of running for long periods of time.


Cordless grinders are more suited for portable and simple tasks. They're good for small garages where there's limited space. High-end Cordless angle grinders keep your metal clean with just as much strength as a corded grinder.

Electric Angle Grinder

This is the most common power type because it can be used for professional or general usage. The power can be drawn through volts. You'll need an angle grinder with 230 volts to complete your basic needs.

Transformers or power grinders range from about 400-3,000 plus watts in power. The lower the wattage, the cheaper the angle grinder will be.

Battery Powered Angle Grinder

Most of the cordless angle grinders you'll find uses Li-ion batteries. This makes them easily rechargeable and a great tool to use when there's no power.

Pneumatic Angle Grinder

Just like the petrol tools, compressed air angle grinders are better suited at professional workshops (workshops, mechanics garages). These devices work by producing air to drive and power the tool. Then they are channeled through pipes, and it directs its flow through the disc of the grinder.


However, compressed air angle grinders operate at a slower speed than their electric counterparts. Because of this fact, compressed air grinders are optional tools at best.

Petrol Powered Angle Grinders

Petrol tools are more suited for site use. Petrol powered tools are large scale angle grinders that are used to cut through blocks and bricks, paving slabs and steel. Your petrol angle grinder is good at both grinding and cutting.

Most petrol tool models have a small petrol engine which directs and drives your cutting disc. Petrol angle grinders are bulkier, but back it up with their immense power.


As a rule of thumb, you'll need a grinder of about 115mm corded for most home users. But if you have more industrial and complex projects to complete, a 230 mm or more expensive grinder model is more than suitable.

What Can Your Angle Grinders Be Used For?

Your angle grinder is a versatile tool that's used for 90% of metalworking projects. When it comes to cutting, they are only good at creating straight cuts. To create curved cuts, it takes time and experience. That’s why it’s important to practice with your grinders to receive the most value out of your grinder.

Wheel Types And Recommended Uses

Aluminum Oxide

Aluminum Oxide is the most used wheel for angle grinders. It's an abrasive that is used to cut through steel, iron, carbon steel, bronzes, and alloy steel. There is usually aluminum oxide abrasives are blended and made for certain complex grinding jobs.


Buffing is a process used to clean and polish metals such as copper, brass, carbon steel, and stainless steel. During this procedure, a loose abrasive is placed on the work wheel. As a result, it gives the leather a velvet like finish by eliminating the surface of the grain.

There are a few buffing methods that are available. For instance, cut buffing involves "cutting down" the copper, brass, or other types of metals while adding color to it. Cut buffing involves using rough buffing compounds to create the desired effect.


Then, there is color buffing. Color buffing is a detailed process that involves using buffing compounds or polishes to give your metal finishes a bright, mirror-like shine. Color bluffing is usually the last step in the angle grinding process where the aluminum and chromium have become completely smooth.


Cut Off wheels are common in the metalworks industry. The wheels are lightweight and remove rust from certain materials with ease. Most blades that are 5 inches or above have enough cut-off power to cut metals into a uniform shape.


Diamond is the hardest material to cut. You'll want to opt for an angle grinder that has a few diamond parts encrusted onto it. This ensures that the diamond pieces can be cut to whatever size you use. While they are more expensive, diamond angle grinder tools are great long term option.



Your fibre disk should not have a diameter above 230 mm. Vulcanized fibre disks are dangerous and eject parts at a speed of 180 mph. Getting hit by this disk would result in a lot of serious pain.


Based on this fact, you'll need an angle grinder that's created for safety. To be safe, never use an angle grinder without a guard.


The flapper wheel helps your grinder wheel regarding speed. They can be either have convex or flat wheel designs. You'll want need to pay attention to the quality of the flapper wheels when searching for an operational angle grinder.

Here are a few tips to follow to utilize the flapper wheel and your angle grinder:

  • Don't place a flat disc that's too tight or too loose on the flange.
  • Only tighten with the manufacturer's accessories supplied with the machine.
  • Keep the screw threads and flanges clean and safe from rust or burrs.
  • Repair and Replace damaged or distorted flanged before using the grinder again.
  • Make sure that the disc is correctly placed to reduce the chance of slippage.

Crimped Wire Wheel Brushes

The crimped wire brush features stainless steel, carbon steel, or brass filaments that have a bent, pinched, or wavy appearance. Crimp wheels that have oil tempered wire might cost extra but last longer than lower quality wheels.

Crimp wire brushes help when creating cleaner breaks in the object. Also, they support uniform and consistent brushing since the tool uses filament tips during its cutting process.

Knotted Brush Wheels

This form of wire brush wheels consists of twists or knots of metal wire. These wheels are usually made of stainless steel or carbon steel. Their main advantage is that they support for aggressive cutting where a lot of force is needed.

Knotted wheels come in either twisted or standard tuft brushes. And, they are twisted for about 2/3 rds of the filament length. With applications where larger wires and a stronger brushing action is required, then the knots can be twisted for their full length.


These brushes have a longer trim to finish complex surfaces with crevices and corners. Also, wire brushes can be used for cleaning out cracks in concrete and asphalt. It's a versatile tool that does heavy duty projects completed in a respectable time frame.


Most of the time, you'll be using your angle grinder to polish and grind your metals. This means that your angle grinder must be at 4 ½ inches or higher to grind such metals without breaking or destroying the final result.


Angle grinders are a cheap resource for sanding wood. To sand your wood, you have to get a grinder that works at over a 1700RPM. This speed ensures that it will remain fast and reliable when sanding multiple stocks of wood at one time.

Silicone Carbide

Silicone carbide is for metals such as gray iron, soft bronze, and brass, and aluminum. It's a great tool for non-ferrous metals and helps users make more precise cuts.


Wire Or Brush

There are a lot of angle grinder models that require a wire brush for it to run property. This mini section details a few wire brushes you'll need to utilize your angle grinder fully.


In some parts of North America (Canada and U.S.), some people have confused this term for pointing. Pointing is used to clean, correct, and finish joints off in newly created masonry. Tuck pointing is used for a different kind of manner.

Tuckpointing is a technique that involves two contrasting colors of mortar. The first color matches the color of the bricks themselves; this gives an impression that high quality and fine joints were created.


Your angle grinder is essential in completing a successful tuck point project. The tools must have a disc size of 125 mm or above to create the results you desire. Make sure your angle grinder has an RPM of 3000RPM so it can cut new masonry pieces in one pass.


There are some technical features that you should look into when getting your angle grinder. Here are some of the most important specs to check for when shopping.

Motor Power

Your motor power is measured in volts and amps. The volts demonstrate how much energy it takes to run your machine. Angle grinders that run on a 120VAC are capable of giving a basic amount of power.

Amps measure your angle grinder’s power. If the grinder has 15 amps or above, it will do a great job at keeping your metals thoroughly polished.


You also want to keep in mind of the RPM of your angle grinder. Other factors such as the rotational speed should not be exceeded. You don’t want to put a 10,000 RPM attachment on a grinder running at an average of 13,000 RPM.

Power Type

There are three different types of power that an average angle grinder uses. Each of them has their pros and cons and useful when used effectively.

  • Battery – Electric powered grinders are perfect when outdoors or in limited spaces. They are easy to recharge and come in handy when there is a power outage. But, some battery powered models are less durable than corded angle grinders.
  • Corded – You’ll want to have this option when you have a stable source of power. While corded angle grinders have a lot of power, some of them take up a lot of energy when used. If possible, try to look for a corded angle saw that’s energy efficient to save money.
  • Pneumatic – This type is powered by air circulating throughout the machine. This is the safest method as the air doesn’t generate heat sparks that can injure you. On average, pneumatic angle grinders have enough power to last for up to 200 hrs.

Wheel Diameter

The wheel diameter measures how much cutting space your angle grinder provider. For instance, an 8-inch grinder has enough durability to cut through stock that’s 2 and 4 inches in depth. But for house hold uses, you’ll only need a wheel diameter of about 4 to 6 inches in order for it to work properly.


Each manufacturer has a chart that displays the different wheel diameters they provide. We suggest getting an angle grinder with a wheel diameter of 5 inches or above so that it can run fast and smoothly without running into any problems.


To find the best angle grinder, you need to know the popular manufacturers that create them. Here’s are the top manufacturers that create angle grinders today.

Continue reading this section to see which manufacturers is best for you. All of the manufacturers have gained their reputation by providing high quality angle grinders at an affordable price


Dewalt (also known as DEWALT) is an American brand of hand tools and power tools for woodworking, industrial, and construction industries. Dewalt is currently owned by Black & Decker; a manufacturer known for making powerful house hold appliances.


Their angle grinders are known for lasting for a long time. If your tool becomes damaged, you’re backed by the company’s 25 year warranty. Buying from this manufacturer ensures that you’ll have a good angle grinder that’s ready to assist you for your everyday projects.


Portable is another American based manufacturer. This company is known for developing the first circular saw, portable band saw, belt sander, and helical drive circular saw.


Porter Cable was founded in 1902. In its early origins, the company’s main goal was to create power tools. As time progressed, they gained international recognition because of the quality, durability, and reliability of their products. Try Porter Cable to get the best angle grinders that are of good value.


Makita has origins in Japan and has gained respect and popularity because of their innovative products. Starting in 1915, this company Makita is known for creating the first rechargeable power tool.


This company is great for those wanting angle grinders that are made out of the latest technological advancements. These tools have a lot of features and tend to last for a long time.


Ever since 1926, Milwaukee has been the leading manufacturer for angle grinders with durability and performance. With a strong commitment to trades, Milwaukee continues to lead the power tool industry with powerful and reliable products.


Milwaukee knows that their users sweat the small details, so do they. Each tool that’s from this company is guaranteed to last for up to 20 years or you’ll receive a refund. Because of this policy, Milwaukee continues to provide excellent customer service and satisfactory results worldwide.


Bosch is a market leader in for power tools and power tool accessories. Each year Bosch launches at least 100 new power tool models into the market. Because of this, they are a trust worthy brand whose products save you a ton of money.


This company began in 2003. As a predecessor to a few exisiting companies, it decided to take a step ahead of the competition. By 2005, Bosch’s power tools and angle grinders sold over $1.7 million power tools internationally. That’s why this is a good brand if you want angle grinders that will remain in good condition.

How To Use An Angle Grinder

Before using an angle grinder, you’ll want to respect to a few safety precautions. These rules help you get the most out of your grinder without causing injury to yourself or others. By following these steps, you’ll know how to make your angle grinder work at a professional level and aid you in your DIY projects.

To use your angle grinder, you need to know how to use it safely. This means you should practice everyday to see how your machine works in order to use to correctly. Here are a few tips on how to use your grinder correctly.

  • Wear gloves and a face shield
  • When changing wheels, unplug the grinder to prevent injuries.
  • Attach the handle and keep a firm grip when using the device
  • Keep bystanders away, anyone that’s in your work area needs to wear safety glasses
  • Keep your work in a position so that the debris falls downward.

Safety Features

Here are a few safety features that need to be considered when searching

  • Safety Gear – You need to wear protective covering when using your angle grinder. Doing so reduces the chances of injury and allows you to use the tool effectively. Wear old clothes and sturdy hand gloves to maximize your angle grinder.
  • Disk Protection – Ensures that your disc is not destroyed once used frequently. People like this feature because it saves them hundreds on buying repairs.
  • Auto Shutoff – When taking up too much power, the tool begins to shut off. This feature is great because it prevents you from wasting energy or leaving the device on too long to cause a hazard.

Maintenance And Cleaning

Here are a few recommendations to help you get better at using an angle grinder:

  • Fix Attachments – Make sure that your attachment securely stay on the grinder without them accidentally fall off.
  • Practice – First, you’ll want to become used to the weight and feel of the power tool when it’s on and off. The force generated by the attachment or rotating disc takes a bit of time getting used to at first.
  • Cut and Grind Away From You – This is the most important rule to follow. You’ll want to cut away from the body. Make sure the guard prevents debris from entering your face.
  • Angle Grinder Position – You need to at least hold the angle grinder at 10° angle. This ensures that your device will run smoothly and won’t create an incorrect cut on your stock.
  • Angle Grinder Position – You need to at least hold the angle grinder at 10° angle. This ensures that your device will run smoothly and won’t create an incorrect cut on your stock.
  • Damaged Grinders and Attachments– We recommend that you don’t use any attachments that are damaged or destroyed.

Closing Remarks

Everyone needs an angle grinder to do the best in their projects and enhance their work quality. While we gave you a substantial amount of information, there are a few extra things to discuss. We invite you to look into our buying guide to find the best angle grinders at a respectable price

Axel Kloch

Your Signature

{"email":"Email address invalid","url":"Website address invalid","required":"Required field missing"}

Subscribe to our newsletter now!