How to Use an Angle Grinder (for Metal, Tiles and Knives)
For those who do a lot of wood, metal or construction work, an angle grinder is an essential tool. You’ll see them in most workshops or building sites where they are used to polish metal or remove excess pieces of material. If you’re new to these types of power tools, you might be wondering how to use a grinder.
In this article, we will be explaining what they are, what they do, as well as the best way to achieve the results you are looking for.
- What is an Angle Grinder?
- What can you do with an Angle Grinder?
- How to Use a Grinder Attachment
- Cut Off Disc
- Diamond Cutting Disc
- Abrasive Discs (Sandpaper Discs)
- Grinding Discs / Wheels
- Flap Sanding Discs
- Polishing Pads
- Sanding Discs
- Wire Brushes
- Non-Woven Fiber Discs
- Fiber Discs
- Flap Discs
- The Equipment Needed
- 1) Create a Template
- 2) Secure the Tile
- 3) Get Your Equipment Ready
- 4) Cut the Tile
What is an Angle Grinder?
Angle Grinders are special power tools that have a spinning blade that allows you to grind, cut, or polish hard materials including metal, steel, and tiles. There are lots of different types available, though, depending on your preference and the type of project you are working on. The main differences are found in the size of the disc and how powerful the motor is.
The Bosch 4-1/2-Inch Angle Grinder 1375A.Find deals for this model and other angle grinders on Amazon now.
However, there are other options when it comes to the power source (which can be electric or pneumatic) and how fast the disc spins (the rpm). Normally, pneumatic powered grinders are better suited to smaller and more precise jobs, whereas electric ones are better for larger projects.
Most tool manufacturers make angle grinders, with the only real differences coming from the amount of power, build quality, cost, and durability.
These pads are used on delicate surfaces, such as paintwork, for polishing.
How to Use an Angle Grinder to Cut Metal
With all of this in mind, it’s easy to get started with your angle grinder to cut metal. Of course, the more you practice the better you will get, but even your first attempt shouldn’t be too problematic.
First, you must be aware of the type of metal that you are working with and what you want to do with it. This will determine the type of disc that you need. If you want to cut a length of rebar, for example, you will need to attach a metal cut-off disc to the grinder. Next, attach the piece of rebar firmly within a clamp so there is no risk of it getting free.
Ensure that the place where you will be making the cut is clear from the clamp. Now, you’re ready to cut. Slowly lower the grinder over the rebar and let the weight of the tool do all the work. Be ready to let the free end of the bar drop to the ground without getting in the way.
There are five types of abrasive disc that can be used for paint removal and cleaning metal.
Use discs no coarser than about 80 grit. Any discs with a grit higher than this and you might find the grinder is removing the paint and even some of your metal too!
Available in two types, Cup and straight. These are used at 90 degrees angle to each other so a combination of both, including small cup sizes may mean you are able to clean right into corners that standard discs cannot reach.
Non-Woven Fiber Discs
These are specifically designed for cleaning and removal of paint on metal. Because they are composed of fibers, they are safer than wire brushes because they are made only from fibers, any loose or flying edges on the disc are less dangerous than pieces of flying steel wire.
Are similar to standard sanding discs except they have a ceramic or Aluminum Oxide grain. They are designed for longer life and reduced heat build up than other similar grinding discs.
They are made from small overlapping strips of reinforced cloth covered in abrasive. Because of their method of construction, lifespan is far greater than standard sandpaper. As the disc wears down, new abrasive is exposed so the disc can continue sanding until the whole disc has been depleted.
Cutting Tiles (4-Step Instruction)
Cutting tiles with an angle grinder is a great way to cut curved edges and round cuts in any kind of tile such as porcelain, ceramic or glass. Angle grinder cutting is not suited for straight edges where a tile cutter should be used. However, if the straight edge does not extend across the entire width of the tile, then an angle grinder may be the only choice.
The Equipment Needed
To cut tiles, you will need an angle grinder that is powerful enough to cut your tiles. As attachments, you need to get some cutting wheels for tiles.
1) Create a Template
Make a template for the correct size or shape of the cut that needs to be made. This can be done by tracing the pipe or edge of wall onto a piece of cardboard using a ship’s curve or a contour gauge to mark around the object shape. Then use the template to draw the shape onto the tile correctly. Try to avoid having to cut large holes in tiles that come closer than half an inch to the edge of the tile because there is a risk the tile will crack. For dark tiles, mask off the area with masking tape and draw the outline onto that so it can be seen easier.
2) Secure the Tile
Secure the tile onto a work surface with help of foam padding or cloth. This aims to cushion the tile so it doesn’t break.
3) Get Your Equipment Ready
Prepare your angle grinder by ensuring it has a continuous blade fitted and not one with teeth. Diamond tipped blades are ideal for cutting tile but blades for steel can generally be used as well. When changing the angle grinder blade, ensure that the center nut is done up the correct way around as they are usually polarized to manage both thick and thin types of blade. If the blade is not fitted correctly it can become loose and be dangerous. If the blade becomes loose it can also vibrate and crack the tile.
For safety reasons, a respirator and face mask should be used for tile cutting.
4) Cut the Tile
Start by carefully cutting the tile lightly at first – ensuring the correct shape is adhered to – and only scoring it with the angle grinder blade. On the second pass, cut slightly deeper and the third pass deeper still. Keep cutting more passes as necessary until the tile is cut right through. For cutting semicircles on the edge of a tile, a two-step approach may be used and a gradually increasingly deep cut can be made alternating on either side of the tile.
Once the cut is complete, the area can be tidied up by carefully using the angle grinder blade to smooth off the newly trimmed edge. For large areas of tile that need to be removed, tile nippers can be used, then finish off with the grinder blade once again.
Angle grinders are great for initial sharpening of very blunt knives and other bladed cutting tools such as axes, choppers and lawnmower blades.
The grinder should be fitted with an abrasive wheel and the blade edge gently offered up to the wheel. The best angle is usually about 45 degrees. Never try to sharpen the blade when it is flush against the grinder. This will only polish the blade but will not sharpen it at all.
Most knives have blades that are naturally curved and this curve should be carefully followed when running the grinder along the blade. Keep the blade moving at all times otherwise you will grind too much off one point of the blade and could damage it beyond repair.
When holding the blade against the grinding wheel, do not try to press hard. Allow the grinding wheel to do the work and gently sharpen the blade. Usually several passes along the entire blade are required before it is sharp. Also remember that most blades are double sided and both sides should be sharpened to the same degree so a pass along one side of the blade should then be followed with a pass along the reverse side of the blade. Use this switching method until the blade is sharp.
To sharpen lawnmower blades, the blade must first be removed from the lawnmower and held tightly in a vise. Remove any loose debris around each blade with a wire brush and then clean with a normal brush. Addressing each blade in turn, hold the angle grinder at 45 degrees to the edge of the blade and slowly sharpen each one in turn on both sides of the blade.
For a super sharp blade, once it has been ground reasonably sharp, polish it off on a grinding stone taking care to keep the correct 45-degree angle of the blade. A little oil can be used on the stone for lubrication while rubbing the blade up and down carefully.
Angle Grinders are versatile tools that can be used to cut or grind a wide variety of materials in place of more specialized tools. By changing the discs as required, an angle grinder will do a great job in a short time. Make sure you get the right attachments for your tool before you start your project.
If you are new to grinding, make sure you follow the safety ground rules thoroughly before you get started. It does not take too long to learn the basics of how to use a grinder. With some practice, you will eventually be able to unlock the full potential of this great tool. If you do not have an angle grinder yet, make sure you read our article about 4 of the best angle grinders (with 3 of them for under 50).
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How to Use an Angle Grinder to Cut Metal?
One of the most popular power tools found in any hardware store, the angle grinder can be used for a wide variety of purposes. From grinding, cutting, and polishing all kinds of materials to sharpening blades and dull edges, this tool is definitely a favorite among woodworkers, metalworkers, and DIYers alike. There are many projects that can be tackled with this piece of equipment, but this time we’re going to FOCUS on how you can use an angle grinder to cut metal and everything else you need to know to do it.
How does an angle grinder work?
Before we start, it might be useful to understand how an angle grinder works first. This tool can be powered by an electric motor or compressed air, and either be corded or cordless. The grinding and cutting are carried out by a disc or wheel that spins at a high speed, usually between 8000 and 11000 RPM. Mounted on a geared head driven by the motor, a disc is a thin, round attachment that wears away as it’s used until it becomes small and needs to be replaced. When a disc is thicker than ½ inch, it’s called a wheel, which is generally used for stripping old paint, removing rust, and polishing. There are many styles of discs and wheels available to suit all kinds of tasks, making the angle grinder a very versatile piece of equipment worthy of being part of your arsenal. As regards features, most grinders nowadays come with an adjustable guard and side handle to allow a safe two-handed operation.
What types of metal cuts can I do with an angle grinder?
Equipped with an angle grinder, you can make rough cuts on small and medium gauge metal stock such as sheet metal, aluminum, rebar, and other mild types of steel. Cutting through dense materials like angle iron and cast iron, and hard items like rods, bolts and metal piping can also be done by attaching the right disc or wheel.
What attachment do I need to cut metal with an angle grinder?
As we’ve mentioned before, discs come in different grains, thicknesses, and sizes. To cut through most types of metal, you’re going to need a metal cutting disc, also known as an abrasive cutoff disc. This type of disc has an edge made of aluminum oxide, a softer bond that results in fast and smooth cuts. For projects that involve thin metal, you should choose a 1.0 mm or 0.8 mm cutoff disc to make a quick job of cutting your piece, leaving a cleaner finish, and minimizing discoloration. There are other types of discs, such as the iron-free stainless steel cutting discs, which, as the name suggests, are used to cut through steel and stainless steel. For this task, you should go for a 1 mm or 1.6 mm disc. For heavier steel and harder metals, such as cast iron, you will need a diamond disc that’s between 1.6 mm and 2.5 mm thick. Bear in mind that thicker wheels cut slower and generate more friction, inevitably leading to discoloration and requiring extra smoothing and polishing steps. Before buying a new disc or wheel, you should make sure that it’s the correct size to fit your angle grinder, and that the maximum RPM of the disc or wheel is higher than that of the tool to prevent damaging either of them and injuring yourself.
How to use an angle grinder to cut metal?
The hacksaw is usually the go-to tool for cutting metal, since that’s what it was originally designed for, after all. However, if you want to make a quick job of it with minimal effort on your part, then using an angle grinder is the way to go. So, let’s go step by step and see what you need to do to cut metal with an angle grinder.
- Safety goggles – to protect your eyes from sparks and debris produced by cutting.
- Earmuffs – to protect your ears from the loud noise produced by the grinder.
- A dust mask or face shield – to avoid inhaling any fumes or dust produced while cutting.
- Gloves – to prevent accidental cuts on your hands.
- Safety boots – to protect your feet from any pieces of metal that might fly down.
- Tightly fitting clothing – to avoid fabric getting caught by the disc.
Preparing your workspace, workpiece, and grinder
Declutter your workspace and secure the floor to prevent any accidents and avoid tripping and falling.
Next, you should mark the place where you want to make the cut. You can use a scratch awl or a permanent marker to outline the design. Once that’s done, you have to hold your workpiece firmly in a bench vise or clamp it down to your workstation to prevent dangerous slips.
Finally, before you plug the tool into the power source, you need to set the disc. To do this, you just have to open the spindle and insert the correct metal disc (we’re going to discuss this in detail later on). Then, you should fasten the spindle nut in place.
Remember to always check that both the tool and the disc are in good conditions before using them.
Cutting the metal piece
Now we can start with the fun part, learning the proper technique for cutting metal with an angle grinder:
- If your grinder is corded, plug it into the power source.
- Adjust the guard so that it’s positioned between your body and the tool.
- Once you turn the angle grinder on, allow the disc to reach full speed to achieve smoother and better results.
- Holding the tool firmly with both of your hands, set down the disc lightly on one of the lines you’ve previously marked at a 90° angle.
- Start cutting by moving the grinder back and forth along each set line. Don’t apply too much pressure and let the tool do the job for you to avoid kickback.
Depending on the thickness of the metal, you might need to apply some pressure, but make sure you do it slowly and carefully.
And that’s it, simply continue the process until you reach the other end of your outline and the piece is cut.
If you need to change directions while cutting, avoid doing it suddenly to ensure that the cut remains precise, and you don’t lose control of the tool.
Finishing the cut
In most cases, cutting metal with an angle grinder will lead to sharp edges that can make your workpiece dangerous to handle. Luckily, you can use the same tool to smooth them and deburr your workpiece.
This step is optional, and whether you carry it out depends entirely on the type of finish your project requires. However, we highly recommend that you do it as it won’t take long and might prevent accidents.
Simply remove the current disc and insert a flapper wheel instead. Position the tool at a 10°-15° angle over the sharp edge and gently run it along the surface, applying even pressure.
Now you’ve learned another of the many uses of an angle grinder!
When you get down to it, cutting metal with an angle grinder is not really a difficult task. As long as you follow the safety procedures and equip your angle grinder with the right disc or wheel, you can slice most metals with ease.
However, you might need some practice before you can achieve clean and efficient cuts. You might want to consider trying out your tool on a piece of scrap metal before getting to work on your piece.
Cutting threaded bolts with an angle grinder
Thanks for reading our guide on how to use an angle grinder to cut metal! You now know the basics of how an angle grinder works and how to operate it. All that’s left is for you to perfect your technique!
Hello and welcome to PowerToolGenius! My name is Liam and for the last 9 years, I have worked extensively with various power tools and accessories. I have tested hundreds of different brands and models and understand the industry extensively and have been working with tools my entire life!
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What Angle Grinder Blade Cuts Metal? | Things You Should Know
Ann Hutchinson is the heart of the team, senior editor and our Head of Product Reviews which means she sets the testing parameters of each group review ensuring that tests resemble everyday use.
An abrasive type 1 or type 27 angle grinder blade can effectively cut through metal of any density. With appropriate cutting techniques and safety protocols, the abrasive blade makes the cutting process extremely safe and efficient.
When tackling woodworking projects, you will inevitably face the conundrum of having to cut through metal. Using a hacksaw for the task can be taxing and time-consuming, and that’s where an angle grinder shows its versatility.
But before you grab your trusty grinder and start working, you should consider a few things about both the power tool and the blade. Let’s explore how you can maximize your efficiency by using the right metal cutting discs and the right techniques.
Cutting Sheet Metal With Angle Grinders
- 1. The Make
- 2. The Durability
- 3. The Thickness
- 4. The Cutting Depth
- 5. The Blade Type
- 1. Using The Right Tools
- 2. Check Machine And Cutting Wheel Condition
- 3. Affix The Cutting disc
- 4. Final Checks
- 5. Turn The Grinder On
- 6. Cutting The Metal Right
- 1. Workplace Safety
- 2. Proper ventilation
- 3. Protective Gear Checklist
- 4. Fire Extinguisher
Angle grinders are capable of cutting through even the densest of metals, provided they are fitted with the right disc. And while grinders are usually used for refurbishing and polishing metal materials, you needn’t limit its use to that.
You can use your angle grinder for a variety of metalworking purposes, ranging from making knives to automobile body parts. Each application of this hand-held power tool can be performed with a metal disc that suits the job well.
A good angle grinder and blade combination will leave no room for complaints once you’ve finished with cutting dense steel and even sheet metal. And so, the role of a blade in metalwork cannot be understated. The right kind of disc will make cutting metal or polishing hard edges significantly easier.
The Right Cutting Blade For Metal
The right cutting blade for metalwork is an abrasive cut off disc, also known as a cutoff wheel. These discs have abrasives embedded in the grinding wheel suited for specific metals, such as aluminum cutting discs using aluminum oxide and silicon carbide abrasives. You have the option of using a one-blade-cuts-all disc, but they may turn out to be less effective than metal-specific abrasive discs.
Here is what you should consider when picking the right kind of metal cutting disc for your angle grinder.
Cutting discs best suited for metals are made with resinoid-bonded abrasives, which results in the abrasive materials being fused into the wheel. In short, the abrasives don’t wear off easily as the disc continues to age, enabling you to cut metals with it for longer.
A cutting disc that breaks midway through a job is less than ideal, which is why the disc should be able to withstand prolonged pressure. To this end, most cutting wheels utilize fiberglass to strengthen them and resist damage when they are used.
Thinner discs cut metal faster and produce much less waste. These range from 0.04 to 0.045 inches in thickness and their point-of-contact with the cutting surface is minimal.
On the other hand, thicker discs cut slowly, produce more heat and can lead to the potential discoloration of the metal they cut. Thicker discs are also more durable, so if you’re willing to accept the trade-off, you may be able to work with them. Their thicknesses range from 0.06 to 0.09 inches.
The Cutting Depth
You can only fit a disc that can cut no deeper than 2.75 inches in a standard angle grinder. It would be wise to keep that in mind while looking into getting the correct cutting disc.
The Blade Type
There are several types of cutting discs designed to cut metal, but the ones best suited for the job are type 1 and type 27. These discs cater to different cutting needs, surfaces, and environments, giving you options when choosing one for your specific task.
Type 1 cutting discs are completely flat and are used to cut metal of all types, including mild steel. The downsides to using these is that they may make it difficult to make a flush cut and may break when used too much.
In contrast, the type 27 discs feature a depressed center that allows your cutting wheel to get closer to the metal. The trade-off with type 27 discs is the high cost and a narrower range of applications.
How To Use An Angle Grinder To Cut Metal
Using The Right Tools
Depending on the kind of metal you’re about to work on with an angle grinder, you’ll need an abrasive disc suited for the job. Hobbyists can get away with using an all-purpose disc for the job instead, as it’s more readily available.
You can also use a C-clamp to keep the metal in place before you begin cutting. The less your metal moves as you cut, the better and safer it will be.
Lastly, you can gather protective equipment such as safety goggles and earmuffs before you begin working. Sparks and stray pieces of metal may fly everywhere, and preventing any unfortunate injury as you work is paramount.
Check Machine And Cutting Wheel Condition
If you’ve been using the angle grinder habitually, you should check the machine before and after you use it. Over time, the handheld power tool can show wear and tear, and any chances of parts breaking and flying off should be reduced to the best of your abilities.
The same goes for the cutting wheel, and you should ensure twice over that it shows no signs of corrosion. If you see any, address the issue at once, or else you may see shattered chunks of the cutting wheel breaking apart and damaging your project. Worse still, it can lead to serious injury if you don’t don the appropriate safety gear.
Affix The Cutting disc
Next, secure the cutting disc properly to the angle grinder and ensure that the disc fits snugly. Type 1 discs need to have the flat side of the nut facing downward against the grinder, while type 27 discs need the protruding part of the nut facing down.
You can perform a few final checks before you begin slicing and shaping your metal. These tests ensure that the cutting process remains as safe as possible while giving you the best results.
- The angle grinder turns on and functions properly
- The metal is secured correctly with the C-clamp
- Your protective gear (safety glasses and face shields) is in pristine condition
- The cutting disc isn’t warped and doesn’t move abnormally
- There are any hazardous objects in your vicinity
Once you’ve marked all these safety points off the checklist, you can move on to the next step of the process.
Turn The Grinder On
When you turn the angle grinder on, you should have the guard face your body. The guard will protect your fingers from getting caught in the cutting blade as you work, but remember to be careful!
You may position the machine in a manner that doesn’t require you to cross your arms while you cut. The last thing you’ll want happening while cutting is the grinder slipping from your hands, after all.
Cutting The Metal Right
Use the following checklist to ensure that you cut the surface well and prevent the cutting wheel from snapping:
- Keep the cutting edge at a 90-degree angle with the metal
- Be patient and take your time cutting the metal
- Apply no more than moderate pressure on the wheel
- Keep your eyes on the cutting surface
- Don’t leave a cut unfinished, as it can lead to jagged metal edges
Angle Grinder Safety Tips
As you cut through metal, sparks will fly in all directions and may end up igniting flammables in your vicinity. These sparks can reach up to 1,800 F, which is why you should clear your workplace of anything that can easily catch fire.
- Wood and sawdust
- Oils and fuel
- Anything that uses aerosol
- Power cables
Sparks may accompany fumes as well since metal discs can produce a lot of heat as they slice through metal. Keep your doors and Windows open and if there’s a strong breeze coming in, position yourself in a way that directs the sparks away from your person.
Protective Gear Checklist
You should wear personal protective equipment while working with metal, such as:
- Safety goggles for eye protection
- Face shield
- Sturdy gloves
In addition to these, ensure that you don’t wear excessively loose clothing to reduce the risk of it getting caught in the machine. Clothing made of synthetic fibers is a no-go, as it can catch fire much more quickly than any organic piece of clothing. Lastly, wearing a long sleeve shirt to cover exposed skin on your arms is also a good idea to protect you from minor burns.
How to mount a cutting disc onto an angle grinder correctly
It’s a no-brainer to have a fire extinguisher within reach and ready to be used in a workshop. Ensure that the extinguisher works properly by testing its functionality regularly and refilling in case it is depleted in a previous use.
Angle Grinder Blade Cuts Metal Conclusion
Thus concludes our guide on angle grinder blades and how they can be used to cut metal. Metal can be quite difficult to slice through, but an abrasive metal cutting disc can effectively do the job.
If you’ve used angle grinders before, you may have noticed that the blade types used for metal are different from the angle grinder blade for concrete. The process for cutting metal requires extra safety precautions with the additional safety hazards that it poses, especially when compared to the process followed with angle grinder discs for wood.
As long as you have the right power tools and safety gear with you, the process is safe and highly efficient. All things considered, you can pick out the right cutting disc for the material of your choice and get to finishing that DIY project of yours!
What Is an Angle Grinder, and How Can It Help Your Metal Fabrication Work?
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We’ve done several articles on metal fabrication as it relates to off-road vehicles, including tubing bending. tubing notching or coping. corner gussets. building rollcages. buying steel, and more. And although several tools are needed for all of these undertakings, quite possibly the most versatile tool that we use for any and all metal fabrication is the electric 4 ½-inch angle grinder. It’s a fairly inexpensive and common tool that can be changed slightly, by using different heads or discs, to suit several different jobs. Because of this, we find ourselves using an electric angle grinder practically any time we are doing any kind of off-road metal fabrication. Here are some details on this versatile tool, one that can take the place of many others and that we definitely would not want to fabricate without. As with any tool, use proper eye protection, gloves for hand protection, and earplugs for hearing protection—a must when using a grinder. Be safe out there, follow warning labels, and use common sense.
What Does an Angle Grinder Do?
The main job of an angle grinder is to grind metal. Many grinders include one type of grinding wheel, a grinding stone, when you buy them, but there are several types of grinding wheels available, and each does a slightly different job. The ability to change wheels is what makes this tool so useful and versatile. It can cut, clean, grind, chop, shape, sand, and more.
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Grinding Stones: Stones are hard and great for removing metal fast. They can also be used to gouge out bad welds or shape steel plate or tubing. They can get hot fast, and they can be unforgiving and can cause unintended damage if used too aggressively.
See all 9 photos 9 photos Grinding stones are kinda the big hammer in the grinder tool box. They are not terribly easy to use and the results are kinda rough, but they do the job at hand.
Flap-Wheels: We don’t know who the first person to create a flap-wheel for an electric angle grinder was, but that person deserves many, many congratulations. This is probably our favorite grinding wheel, and it can do many, many jobs. Our fab tool setup includes four or five angle grinders, and you can bet the one we use the most has a flap-wheel attached. This tool can be used to smooth the edges of plate and tubing, to grind down welds, clean off paint and dirt, and more. It’s also great for coping tubing or adding a bevel to plate for a good weld. These discs are fairly forgiving and easy to control when doing precise work, too—even on plastic (see below).
See all 9 photos 9 photos We’re unsure if it’s just us, or if flap-wheels are really that versatile, but we use this style of grinder wheel more than any other. They can grind, shape, sand, clean, and more. They can gouge metal, but they are very useful for all-around use. It’s surprising how fast you can remove hard metal with what is basically just sandpaper.
Sanding-Discs: These are little more than some coarse sandpaper cut into a round disc with a hole in the middle, and they make a great tool when trying to maintain a flat surface. Unlike stones or flap-wheels, which can gouge metal, a sanding-disc keeps the surface that you are grinding down a weld on or cleaning plasma-cutter slag from relatively flat.
See all 9 photos 9 photos Sanding-discs definitely have a place in the fab world. They are great at grinding flat surfaces, cleaning slag from plasma- or torch-cut parts, and more. They don’t gouge so you can’t really use them to shape metal unless the shape you are going for is flat.
Cutoff Wheels: Much like a grinding stone, although much thinner, a cutoff wheel on a grinder is great for making cuts in all kinds of metals. It basically turns your angle grinder into a miniature chop-saw that can be used to cut metal and more. Cutoff wheels are good for making precise and relatively straight cuts in tubing, sheetmetal, and plate. If you doubt us, just look at all the quick videos on metal fabrication online—almost all of them rely on an electric angle grinder with a cutoff wheel. We also like to use cutoff wheels to remove brackets from axles and framerails—we just cut at a 45-degree angle into the weld, toward the unwelded root of the bracket, then whack the bracket with a hammer and we’re nearly done. You can also sometimes use a cutoff wheel to make a slot for a flathead screwdriver in a broken bolt.
See all 9 photos 9 photos If we use the flap-wheel most on our angle grinder, we probably use a cutoff wheel second-most. It’s great for cutting welds, making plunge cuts in sheetmetal, cutting rectangular tubing, and maybe some mild grinding. Cutoff wheels can also be dangerous. They don’t like being forced into a curve, and can come apart quickly, becoming hot, sharp projectiles. Be careful!
Wire-Wheels: Like a wire brush, wire-wheels are great for cleaning surfaces before and after a weld. These tools are great for removing less stubborn weld splatter, or cleaning off rust, oil, or paint from an area you are about to weld on. As said, they are like a wire brush, but with the speed of the grinder they remove more material faster. Just be careful as they also tend to eject metal wires at high rates of speed.
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Sanding-Discs: Yeah, we touched on it briefly above, but it bears repeating: There isn’t a much better way of removing paint, surface rust, or slag from torch- or plasma-cutting than using a sanding-disc on an electric grinder. Again, this tool keeps the surface flat, and although a flap-wheel will do a similar job, it can gouge the surface.
Sheetmetal and Plastic
Cutoff Wheels: Again, we mentioned these earlier, but didn’t get all the info we wanted to share out above. When working on sheetmetal, a cutoff wheel is a great way to start a cut, by plunging the relatively thin blade into a flat sheetmetal surface. We often do this to start a cut in sheetmetal that we may finish with an air-saw or reciprocating saw. You can also cut plastic with a fresh cutoff wheel, but know that they often melt the plastic creating a substance similar to napalm that is hot and sticky and will burn you if you touch it.
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Flap-Wheels: You know we like flap-wheels because they are very versatile for metal-work, but they also are a great tool for cleaning up cuts in sheetmetal and on plastic. With some practice, you can use a flap-wheel to smooth out a wheelwell cut made by a plasma cutter, reciprocating saw, or other method. They are also great for shaping cut edges in plastic fender flares, fender liners, moldings, and even interior plastic parts. They too will, while grinding plastic, melt it, turning it into something akin to napalm, sticky hot goo that will burn flesh if you get it on you.
Corded or Cordless
Until recently, all we used were corded electric angle grinders or smaller pneumatic air grinders (below). That’s because, although battery-operated equivalents were available, the batteries were easy to use up in short order. With frequent or prolonged use, a corded angle grinder is our preference, since you don’t have to stop part way through a job to charge or even just to swap a battery. Still, the portable nature of a cordless angle grinder can’t be denied.
See all 9 photos 9 photos Twist-on sanding pads are what we use most on our pneumatic angle grinders, with these 3M-style abrasive pads coming in a close second. You can do some shaping with a pneumatic grinder and a sanding disc, but they tend to catch more in corners and on sharp edges than when used with an electric grinder. You can also use pneumatic grinders with some wire-wheels or brushes, and mandrels for cutoff wheels are available as well. The cutoff wheels are small and thus very useful in tight spaces.
Similar Tools That Do Almost the Same Thing
We mentioned pneumatic angle grinders (above), and the fact is that they can often be used to do the same jobs as an electric angle grinder. You can add sanding-discs, cutoff wheels, wire-wheels, and a few other types of cleaning heads to a pneumatic grinder. Also, they are often more compact and easier to control than an electric angle grinder. We also love them for cleaning up gasket surfaces when used with a 3M-style abrasive wheel. Truth is, in a pinch, if all you had was a pneumatic angle grinder or two, they could take the place of an electric angle grinder. But for us, there just is no fabrication undertaken without our favorite tool.