If you are serious about metal fabrication, DIY or even upcycling, you probably either own or have considered buying an angle grinder.
Here's why we think an angle grinder should be an essential part of the toolbox...
This article covers:
- What is an angle grinder?
- Why buy an angle grinder?
- Which angle grinder disc do i need?
- Staying safe
- Getting started
An angle grinder is a handheld power tool that can be used for a variety of metal fabrication jobs that include cutting, grinding, deburring, finishing and polishing. The most common types of angle grinder tools are powered by electricity; either corded or battery powered.
Which abrasives discs you select to use with your angle grinder depends entirely on your specific application and the material you are working with. Read on for more on this.
Versatile and easy to use
It's the most versatile tool in the box and should be a staple of any shed or workshop but we aren't just saying that because they work perfectly with many of our abrasives!
An angle grinder tool with the right disc can replace numerous tools and make the most tedious, labour intensive jobs quicker and easier.
Better yet, they are easy to control and any novice with the correct safety precautions can pick up an angle grinder and start working. This makes them perfect for DIY projects.
What is most common angle grinder size?
Angle grinder tools come in many different sizes, the most common size sold in the UK is 115mm. This sized model is light, precise and generally very easy-to-use; making it a great choice for the beginner and professional alike.
A wide choice of angle grinder models and brands available
Unlike a lot of specialist tools and abrasives, you can walk into any nearby hardware store in the world and find an angle grinder for sale.
There are huge number of different models and brands to choose from, at varying price points.
Your budget, your level of usage, and your experience should be the key influences over which angle grinder you purchase. Don't go spending over the odds on a high-end model that's only going to be used twice a year.
If you're not planning to use an angle grinder for long periods at a time or are working at different locations, then a cordless angle grinder may be more suitable. Take a look at our guide to a cordless angle grinder, to find out the right abrasives to use and how you can improve the life of your battery powered machine.
So you've purchased your angle grinder, now which discs do you need? In the first instance you need to determine the type of material you are working with – metal or masonry?
Then, what are you doing to the material, is it cutting, grinding, stripping, finishing, or all of them?
Angle grinder discs for cutting metal
These products can be very broadly categorised as either for cutting or grinding.
Cutting metal: Cutting Discs
Metal cutting discs are designed to cut through metallic items as quickly as possible.
The type of disc you choose will depend heavily on the hardness, thickness, and the metal itself.
Thinner cutting discs such as the Ultra-Thin range of 1.0mm and 1.3mm are ideal for metal pipes, thin gauge metals and tubular workpieces.
Logically therefore, a thicker heavy-duty disc is used for more robust pieces of metal where more stability is required.
Our top tier cutting discs are found in the Norton Quantum3 range.
With a self-sharpening ceramic grain, Norton Quantum3 discs are fast, effective, and comfortable to use; performing time after time.
Grinding metal: Grinding Wheels and Flap Discs
Whether you are preparing carbon steel for painting or finishing a weld seam , grinding wheels and flap discs are essential accessories for the angle grinder.
Selecting the right grinding wheel can be quite complicated and will depend heavily on the desired surface finish you require from your metallic workpiece.
A highly polished, decorative finish on stainless steel for example requires more steps and usually a higher degree of technique than simply roughing the surface of carbon steel to improve paint adhesion.
Why not read our definitive guide on choosing grinding wheels for more information?
Stripping metal: Stripping Discs
For stripping heavy coatings (such as paint or rust) from metal or wood, you will need to choose a coarse grit fibre disc, flap disc or Norton Rapid Strip disc.
Depending on the condition and amount of coating to be removed from metal, you could opt for a coarse abrasive.
Starting with a coarse grit will allow you to strip the coating quickly and minimise loading of the disc, however it may impart deep scratches on the surface.
For rust removal, use a 60 or 80 grit flap wheel or rapid strip disc.
Rapid Strip discs are particularly suited to removing rust and de-burring metal without damaging the workpiece itself.
Angle grinder discs for cutting concrete and masonry
Generally, a diamond blade would be the best choice for cutting concrete and masonry.
Unlike the cutting and grinding wheels for metal, a diamond blade is predominantly metallic product itself.
Its basic general structure is a steel centre with outer segments containing synthetic diamond fragments that give the blade abrasive qualities.
These diamond segments are ideal for cutting concrete, bricks, and building materials, and natural stone.
Once you’ve picked the right disc for your project, you just need to make sure you find the right size and speed for your specific angle grinder.
Why not try the Extreme Universal Turbo from Norton Clipper?
Setting the correct speed
Angle grinder discs have a maximum safe RPM that they should be operated at, which prevents them from breaking apart while in use and potentially causing an injury.
Make sure that your right angle grinder tool does not exceed the recommended RPM for the product you are using, bearing in mind that most right angle grinders run at a fixed speed of around 11,000 RPM.
Personal Protection Equipment
Once you’ve chosen the right angle grinder discs for your project, you need to prepare your work station.
Whatever you’re working on, you’ll be generating dust, flying debris and possibly even sparks.
To keep yourself safe, make sure you wear work gloves, a dust mask, safety glasses and a full face shield.
It’s also a recommended that your work somewhere that is properly ventilated, and always use the safety guard during operation to protect yourself.
In the extremely rare event of wheel breakage, the guard is designed to project all disc debris away from the operator, so always ensure no-one is in the potential path of debris if the worst would happen.
For the safest operation, we'd recommend that your angle grinder features a 'dead man switch' too.
This means you’ve got to keep the switch in the on position while in use, so if you were to let go of the grinder, it would switch off, reducing the risk of injuries.
Check the expiry date
Cutting discs and grinding wheels for the angle grinder have an expiry date which you need to pay attention to.
To find this, simply check the inner metal ring on the disc and look for a date stamped there.
So now you have chosen the correct angle grinder discs for your specific application, safely set up your work station and taken all necessary safety precautions, below are some tips for how to work on each material.
How do you cut metal with your angle grinder?
When it comes to cutting metal, a right angle grinder saves a lot of time and effort versus using a standard hacksaw.
Ensure that you clamp the workpiece securely in a vice and select a suitable metal cutting disc.
Make sure each side of the cut is supported, so there is no possibility for it to move and ‘pinch’ the disc as you are cutting, potentially causing wheel breakage.
Hold the grinder tool straight and use light pressure to cut through the metal, let the cutting disc do to work, do not try to force it through the workpiece.
Move the disc backwards and forwards along the cut, take care not to twist the grinder as this will cause the disc to warp and bend.
Too much pressure will also result in the cutting disc wearing prematurely, which means you’ll be replacing worn out discs more often than you want to!
Cutting ceramic tiles, concrete and stone with an angle grinder
An angle grinder can be used to replace a larger tile saw to cut ceramic tiles, concrete paving stones, and many other types of stone.
For this type of work, you would need either a cutting disc that specifies use with masonry or (more commonly) a diamond blade.
Diamond blades often cost a bit more but will last significantly longer and cut faster.
Another handy use for the right angle grinder is cutting ceramic tiles.
For this application you will need to use a continuous rim diamond blade that is designed to cut through hard tile and leave a smooth cut.
An ordinary segmented diamond blade would be unsuitable for this kind of work as it would almost certainly cause a a rough, chipped edge.
When cutting paving stones, stone and tile, make sure the workpiece is secured before cutting.
Using light to medium pressure, move the grinder in a back and forth motion through the cut.
This helps remove dust from the cut and allows the wheel to cut faster. It is important not to twist the grinder when in use as this can cause the disc to warp and with some lower quality blades, the segments themselves to break off.
For an in-depth look at how to use an angle grinder, watch the recording of our Norton Live webinar covering how to cut, grind and finish: