Angle Grinder Blade Types and Uses. Angle grinder cutting wheel

Right Angle Grinding Abrasives: Know Your Options

perators have choices when selecting an abrasives product to grind down welds or to perform beveling on a workpiece. Choices include grinding wheels, flap discs, or fiber discs. All three excel at removing large amounts of metal. But, what unique advantages can these abrasive products provide?

Let’s start with grinding wheels, the roughest and toughest of the three. They are created by combining resins, fillers, and grain together into a mix and forming the wheel using pressure, time and heat. Once cured, the wheels are extremely hard and can handle the most aggressive grinding applications.

Flap discs are made out of cloth backing and abrasive material. Most of the material used for flap discs can be also used for belts, quick-change discs, and other shaped products. The material is slit and cut into small pieces called flaps. These flaps are held in place by adhesive, pressed onto the backing plate, then cured to set the adhesive forming their shape. Flap discs primarily have two types of backing plates, fiberglass or plastic. Fiberglass is more rigid and less flexible than plastic. If the job is more demanding, fiberglass will be able to remove more material faster. Most plastic backing plates are trimmable to help increase the life and offer additional conformability. Both backing types for flap discs are available in Type 27 wheels which are used at angles from 0-to-15 degrees, and fiberglass backing is used in Type 29 wheels from 15-to-25 degrees.

Fiber discs are also made with abrasives, but the backing is vulcanized reinforced paper. They are strong enough to handle a resin-over-resin coating system, and they are also able to withstand heat generated during grinding.

Grinding wheels and flap discs do not require a back-up pad like their cousin, the fiber disc. Fiber discs require a back-up pad because their reinforced fiber backing alone is not strong enough to withstand the forces of grinding. All three products are available with a 5/8”-to-11″ backing plate or hub insert. The benefits of the 5/8”-to-11″ are easy on-and-off operation without the need for tools, which reduces the change out time.

CARE AND STORAGE

Each product requires a great deal of care, including stock rotation, to ensure safe use. Fiber discs must be stored in proper conditions to prevent curl. If the environment has too much humidity, the backing will absorb the moisture, causing a sand-side in curl. Too little humidity and the backing becomes dry and starts to shrink, producing a sand-side out curl. The sand-side out curl will make it difficult to lock the fiber discs onto the back-up pad and the product could be too dry which may possibly result in breakage. The sand-side in curl will make the edges of the discs more easily able to snag the workpiece, leading to damage or operator injury.

Norton Quantum3 combo wheels provide substantially faster grinding for increased metal removal and longer wheel life, with less operator fatigue.

Grinding wheels also need to be stored properly. They should be kept in an area that is not exposed to high humidity or freezing temperatures and they should be kept away from areas that are vulnerable to water or other solvents, because these extremes can affect the bond of the wheel. Most wheels need to be stored in their original container. When the abrasive wheel is mounted on the grinder, it is best to have a holder that can help prevent the wheel from potential damage. If the grinder is dropped, placed on a surface with excessive force or is impacted by other objects, the holder helps protect the wheel from damage. Always inspect wheels before grinding and discard any wheel with cracks or damage.

Flap disc storage is recommended at 40-to-50 percent humidity and 60-to-80 degrees Fahrenheit. It is best to store flap discs in their original container and rotate stock as you would with grinding wheels and fiber discs. Inspect the discs before using and discard if any flaps are missing.

Using all three products requires proper personal protective equipment (PPE) and a clean work area free of bystanders and flammable material.

USAGE

Grinding wheels are extremely tough, but damage can result when a wheel is dropped on a table or hard surface. Care should always be taken to prevent the wheel from becoming damaged, and if a wheel is compromised, it should not be used. By using a damaged wheel at 10,000 rpm, everyone in the room becomes susceptible to a potential accident waiting to happen.

It should also be noted that grinding wheels require more training than flap and fiber discs. A Type 27 grinding wheel requires a 30-degree angle while Types 28/29 require 0-to-15 degrees. Operators that use a Type 27 wheel too flat can increase the bevel, which generates heat and leads to wheel failure. Apply too much of an angle and the wheel will likely start spalling, which means it will break down prematurely. Grinding wheels can be hard to handle because they remove large cutting fragments from the workpiece, and the noise level is greater than its counterparts.

Flap discs also require proper care to maintain their integrity. The flaps that make up a flap disc are held down with strong adhesive, but that does not make the discs indestructible. If used improperly, such as at excessive angles, or jabbing the discs into tight places, or on an extremely sharp or rough workpiece, the flaps could potentially come apart during use. Further, without proper PPE, the operator or others in the area could get hurt. Flap discs require slightly more pressure than fiber discs to wear away the cloth backing to expose more sharp grain. Most operators leave plenty of life on used flap discs instead of applying enough pressure to wear away the cloth backing. Also, insufficient force will cause “capping”, preventing full use of the product. Capping is when metal adheres to the abrasive grain due to excessive heat and insufficient pressure. This can prevent the grain from fracturing which is needed so it can re-sharpen itself.

Fiber discs require less force to do the same amount of work as grinding wheels or flap discs. The required back-up pad provides a strong backing, similar to flap discs. However, the coating method on the paper allows for an aggressive cut similar to grinding wheels. Most operators prefer the higher cut-rate, lower tool vibration, noise reduction, and ease of use of fiber discs compared to grinding wheels. Fiber discs must be used correctly and with proper PPE. Back-up pads must be in good condition and must be made to be back-up pads. Using old fiber discs or cutoff wheels as back-up pads is dangerous and should not be attempted. Discs that have extreme curl should not be used because they can snag the workpiece, or become too brittle and break while under force. Fiber discs may not have the life of flap discs and grinding wheels, but the lower price point and versatility make them an operator favorite.

Norton BlazeX F980 fiber discs significantly increase cut rate and life in stainless steel and harder-to-grind materials.

As mentioned previously, all three products are safe to use if stored correctly and used properly while wearing the correct PPE. Millions of these products are used safely to build, repair, and create many of the objects around us. While these products are safe when used correctly, it is important to remember never to use a damaged wheel or disc. Damaged wheels or discs should be disposed of immediately and a new one should be fitted for operation.

LIFE AND CUT-RATE

In a test, welds measuring 2″ × ½” × ¼” were created by a robotic welder, and removed using a grinding wheel, flap disc, and fiber disc. The test results were as follows:

• Grinding Wheel: First used for removing the weld was the grinding wheel with high quality ceramic abrasive grain. It only took 25 seconds to remove the weld.
• Flap Disc: Next was a ceramic 36 grit flap disc with a fiberglass back plate. It also only took 25 seconds, comparing nicely to the grinding wheel.
• Fiber Disc: The ceramic 36 grit fiber disc was tested last, and it had something to prove. It removed the same amount of weld as both the grinding wheel and flap disc, but it only took 17 seconds at lower amps to get the job done.

Norton Blaze R980P flap discs have a premium ceramic alumina grain for long life when grinding stainless steel, cobalt, chrome, Inconel, titanium and other hard-to-grind materials.

If the test was extended to grind for a longer period of time, or if a much larger weld was present, the fiber disc would lose its cut-rate, depending on force and type of metal, in approximately 10-to-14 minutes. Flap discs will continue to wear away and expose new grain, allowing them to last longer than a fiber disc, but their life would be approximately one hour, again depending on force and metal type. The grinding wheel is a long-distance runner and can last longer than flap discs and fiber discs, while doing the same amount of work. Grinding wheels cost more per unit, but if it takes two flap discs or five fiber discs to do the same job, the total cost might be greater using those, not to mention the time it takes the operator to change the discs.

Here are some additional tips:

• When working on a thick weld on a long I-beam or any large piece of metal, a grinding wheel should be the first abrasive product choice.
• Removing or blending regular size welds can be done easily with fiber discs or flap discs.
• Grinding wheels are preferred when metal removal is your only objective, but will not be an optimal choice if the final desired result is polishing.
• Fiber discs will allow for feathering the area with a soft or medium density back-up pad, at a faster pace.
• Flap discs are more rigid but leave a nicer finish when compared grit-to-grit to a fiber disc.

All three abrasive products have unique advantages and can overlap applications to some extent. Following some basic rules of thumb and consulting with your abrasives supplier for their advice will help you achieve optimal results.

Cutting-Off Wheel Breakages. Causes and Cures

Learn the many reasons why a wheel might break in use and how you can prevent cutting-off wheel breakage.

Do’s and Don’ts of Flap Discs

Prevent flap disc breakage and personal injury by following these safety practices.

Safety Posters Now Available

Announcing the NEW Norton | Saint-Gobain Abrasives safety poster!

Angle Grinder Blade Types and Uses

An angle grinder may be used in any trade field, including construction, metallurgy, and even woodworking. It is a far more versatile power tool than you might initially believe.

You may use them with a wide variety of angle grinders wheels and discs, including grinding wheels, cut-off discs, flap discs, and more, making them adaptable. You can do anything with these various wheels, from cutting metal sheets to scraping paint.

We’ll look at the wide varieties and their applications in this article. After that, you’ll know more about how each one operates and which one you’ll need to complete a particular activity.

Types of Angle Grinder Blades

GRINDING WHEELS

Due to their versatility, grinding wheels, also known as grit discs, are the most recognizable and widely used of all the discs on the market. To handle particular applications, they come in a variety of diameters up to 10 inches and with variable levels of thickness.

There are various grit levels for grinding wheels. Higher grit numbers will be less coarse than lower grit values, and vice versa. Choose a high-grit grinding wheel for a smoother finish. Low-grit grinding wheels are ideal for quick, clumsy labor where the final appearance of your item isn’t as significant to you.

A grinding wheel is mainly used to remove extra material from a project’s surface. You may use a grinding wheel for various tasks, such as cleaning up cuts and preparing metal for welding, making it an all-purpose disc.

CUT-OFF WHEELS

Cut-off wheels serve pretty different purposes despite their similar appearance to grinding wheels. The cut-off wheels are recognizable by their thin design, which enables them to remove metal bars and sheets more precisely. Wear the appropriate safety equipment because these discs can be hazardous due to their slim design.

Different wheel thicknesses are available, and each has advantages and disadvantages. Although you can do cuts more quickly on thinner discs, they will be more brittle. A thicker disc is more durable and less likely to deform after being cut. The disc will break if it is bent in an unusual way, scattering dangerous pieces around the room.

Cut-off wheels are typically employed to slice various metal objects, such as bars, tubes, and tiny pieces of sheet metal or plates. You can also use them to shorten excessively long bolts or remove welds.

FLAP WHEELS

The flaps are a term for the multiple overlapping abrasive sheets that make up the disc. Although flap wheels don’t look like a regular grinding wheel, it functions similarly. It distinguishes itself by giving your project a significantly more refined finish and is frequently used for finishing work. Different grit options are available, and they all follow the same principle: the more grit, the smoother the finish.

After working on a surface using a grinding wheel, you’ll typically transition to a flap wheel. The revolution will continue to function at its peak until all of the grit has been removed because as the flaps deteriorate, more determination is revealed. These angle grinder wheels are frequently used in metalworking, fabrication facilities, and autobody shops. They eliminate rust, polish surfaces, and remove minor flaws like burrs or scratches.

WIRE WHEELS

Another effective method for removing paint from a character is to use wire wheels. Although wire wheels come in various designs and serve multiple functions, they all essentially consist of wires that protrude from a circular base.

They have bristles that are either thick, twisted, more abrasive for quicker, more accessible work, or thinner, straighter, and less abrasive for more delicate, precise work. Be careful because they can cause scratches on the surface even when used on softer materials. Various angle grinder accessories are intended to remove rust or stubborn polish metal quickly.

DIAMOND-CUTTING WHEELS

Diamond cutting wheels are just as durable as diamond blades and are among the most rigid blades on the market. Diamond grits are embedded in the edges. They typically last longer than conventional blades because of their rugged construction.

The disc will last longer and be more durable if the cutting rim is higher. In wet and dry cutting processes, you can utilize diamond cutting discs on some of the most complex materials, such as masonry or stone. In the vast majority of programs, you can work quickly and efficiently.

PAINT STRIPPING WHEELS

Wire wheels frequently substitute paint-stripping wheels when removing paint from metal surfaces. These wheels are often referred to as strip discs. Since they won’t harm the material, they perform best when working with slightly more sensitive fabrics like soft metals, wood, or fiberglass. Strip discs are more suited to working on more delicate surfaces without endangering them because they are made of poly-fiber material. You can also use them to get rid of epoxy or other leftovers.

CONCRETE GRINDING WHEEL

A grinding wheel attachment is available for polishing or removing concrete from your surface. Wheels for grinding concrete come in a variety of sizes and designs. For concrete, fiberglass and other abrasive materials are used.

Stone, masonry, granite, marble, and other complex materials can all be ground using concrete grinding wheels. These discs have a structure that makes them durable over time, but they eventually wear out, so you should replace them when they start to chip.

When using an angle grinder, always be careful to follow the correct safety precautions and wear any necessary personal protective safety equipment. The disc size and angle grinder RPM must be compatible to prevent disc damage, which could result in injuries. Every day, the leading power tool manufacturers create new safety innovations to make using your angle grinder safer for you and those around you.

Best Angle Grinder Wheel for metal

Are you looking for the best angle grinder wheel for cutting metal? There are so many good angle grinder wheels out there, that it can be hard to make the right decision.

What makes the best angle grinder wheel for metal?

When buying an angle grinder wheel for cutting metal you want to keep the following things in mind:

• What the grinding wheel is made of – In general, you want to choose a grinding disc that is made from Aluminium Oxide
• Grain concentration – The higher the grain of a grinding wheel the cleaner the cut. For dense materials like metal and steel, you want to use the highest grain possible.
• Durability – A high-quality grinding disc should not wear very fast.
• Price – Price is the final thing you want to keep in mind when looking for a grinding wheel. They may seem cheap but, in the long run, you can save a good amount of money.

Best angle grinder wheels for metal

These are our favorite angle grinder wheels for metal:

DeWALT General Purpose (DW4523)

• Made of aluminum oxide
• High grain concentration
• Very durable
• Best price/quality

Angle grinder wheels come in a million different grains and sizes. It comes as nobody’s surprise that DeWALT is one of the most popular disk manufacturers. They offer a three-year limited warranty on most of their products. Also, they are proven to be one of the best power tool manufacturers. You really can not go wrong with them!

These grinding wheels are ideal to pair with a DeWALT grinder. Read: The best DeWALT angle grinders to find out which are our favorite DeWALT angle grinders.

Specs

This grinding wheel is made of aluminum oxide. A longer-lasting and safer material than some other grinding wheels on this list.

The DeWALT DW4523 all-purpose grinding wheel can be used for all 4 1/2″ inch grinders.

Truswe metal Cut Off Wheel

• Compatible with all 4-1/2 inch angle grinders
• Made of aluminum oxide
• reinforced by double fiberglass mesh
• Great price/quality

Truswe is a less-known brand that specializes itself in grinding disks. For this reason, they produce some of the best quality angle grinding wheels on the market! This grinding wheel in particular is extra thin and super durable. Truswe metal grinding disks are made for 4 1/2 inch angle grinders.

They are made of Aluminum oxide. These fibers stick together making this grinding wheel safer than others on this list. The aluminum oxide will not shatter and will wear less than other materials.

The only thing to keep in mind when buying Truswe grinding wheels is that they come in a pack of 50.

EZARK metal Cut-Off Wheel

• Made of iridium-plated white corundum
• Fast, precise, and clean cutting performance
• Tough abrasive cutting discs
• Decent price/quality

EZARK grinding disks are made of Iridium-plated white corundum. These are in general a bit more durable than standard Aluminum oxide disks.

However, the biggest drawback of corundum is that it has a higher risk to shatter. Therefore we recommend extra safety protection when you are using these grinding disks.

Unfortunately these disks also only come in a pack of 25.

Are you looking for an angle grinder that can be used with these wheels? Check out our guide: Best cordless angle grinders

Frequently asked questions

Can I use an all-purpose grinding disk for metal?

You can! However, keep in mind that these wheels tend to wear out quicker while grinding metal compared to a dedicated metal grinding wheel.

What started as a passion for power tools has now grown to become our full-time job. With our team of 4 people, we are constantly reviewing the latest tools on the market!

What Is an Angle Grinder, and How Can It Help Your Metal Fabrication Work?

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.

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.

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).

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.

Cutting

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.

Cleaning

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.

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.

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.

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.