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A Complete Guideline on Angle Grinder

An angle grinder- a very useful welding tool- is also known as a side grinder or disc grinder.  This handheld power tool is commonly used for grinding and polishing. Although this tool was originally developed for the rigid abrasive disc, its interchangeable power source has given it a wide range of versatility including cutting, cleaning, etc.

What is an Angle Grinder

As I said earlier, an angle grinder is a welding tool, commonly found in workshops that deal with metal fabrication and other types of metalwork. These handheld tools are available with consumable stone discs or blades of different sizes and amperages. The blades or disc spin at a high speed to do the grind, polish or cut metals while larger disc and higher amperages are typically used for industrial projects like beveling walled pipe.

Use of Angle Grinder

Angle grinders are widely used for metalwork and construction, however, their multi-purpose applications allow replacing traditional tools. Since it has a diverse range of applications, depending on purpose different types of the disc are there like a cuts-off disc or diamond blade, abrasive grinding discs, grinding stones, sanding discs, wire brush wheels, and polishing pads. Let’s have a look at the diversified use of angle grinder:

Cutting Metal: with the right disc, a grinder can cut thin metal boards easily. The metal cutting wheels however can be used to cut rusted bolts or iron fencing since they contain aluminum oxide as an abrasive.

Cleaning and Preparing Metal: another popular use of angle grinders is removing excess material from the base metal prior to welding. Excess material on the workpiece can result in cracking especially in the case of MIG and TIG welding as they don’t work well with debris.

If you are thinking of using a wire brush to clean off paint, rust, and mill or sandpaper to clean gritty metal then I would say angle grinder is definitely a faster option for these jobs. An angle grinder with a sand disc can perform even better than your imagination.

Emergency Rescue: not only cutting or cleaning metal, but an angle grinder is also a perfect tool for emergency rescue as it can cut cement blocks as well as metal frames.

Cleaning up and Finishing Weld: SMAW or Shielded Metal Arc welding is a messy process and leaves a lot of debris. But using an angle grinder is an effective way to get rid of it. Not only that, by using a flap disc you will be able to smooth or polish the metal piece before powder coating or painting.

How to Choose Right Angle Grinder

The most common and important factor in choosing an angle grinder is the right size of the disc and the power of the motor. The disc size and power increase simultaneously. The disc size is usually measured in inches or millimeters. In the United States most commonly used disc sizes are 4 inches, 4.5 inches, 5 inches, 6 inches, 7 inches, 9 inches, and 12 inches. Other factors are power sources (pneumatic or electric), RPM, and arbor size.

Types of Angle Grinder

The two main types of angle grinders are

  • Cordless grinder and
  • Corded grinder.

Apart from these two types, there are

  • Pneumatic Angle Grinder: pneumatic angle grinder is the ideal example of performance and durability. It is the perfect tool for cutting and shaping the metal workpiece. Pneumatic grinders require connection to suitable air compressor units and are used for light jobs that need precision. Some pneumatic grinders come with throttles that provide high-level control over performance like feather edging and speed grinding.
  • Variable Speed Angle Grinder: variable grinders are suitable for a wide range of works the speed can set at different ranges. You can set the disc at a high RPM to complete any work with high precision. Some models of the variable grinder are available with paddle switches that enhance the control over the tool during work.
  • Straight Angle Grinder: the 90 degree Wheeland attached different grinding stones make a straight grinder a perfect tool for grinding outer edge and inner parts. Its unique disc angle makes it more suitable for some work than the standard angle grinder in some instances.

Cordless Grinder

As the name suggests there is no cord attached to the tool and trust me! It is a great relief that you do not have to drag a cord behind you. However you have to finish work within a limited time so for heavy-duty, it is better to have two or three batteries charged.

These highly practical grinders are usually used in different worksites and can be carried around without being concern about a power outlet. This type of grinders are very helpful for using on ladder, scaffold, boiler-like room, inside large diameter pipe and confined place.

Mere 10 years ago cordless angle grinder was only suitable for less intensive DIY works around the house and the runtime was extremely low. Back then chorded grinders were the king and from professional to personal they were unbeatable.

Now in 2021, the cordless grinder has improved significantly with exceptionally refined components like brushless motors, and improved battery capacity and the credit goes to lithium-ion technology. To choose the best, read about the Top 5 Best Cordless Angle Grinder of 2021.

Advantage

  • The first advantage of cordless models is the accessibility. Since there is no cord attached to it, it is really easy to access any small or confined places without being worried about power sources.
  • Cordless grinders are the perfect tool for working on vehicles because there are some critical points or limited spaces where corded grinders can’t reach properly.
  • Using a corded grinder in a working site might create hazards. Usually, a working site is busy with tradesmen and anyone can run over cables across the floor or electric points. Using a cordless grinder can solve all these problems.

Disadvantage

Like all other tools, cordless angle grinders have some disadvantages.

  • The first disadvantage is, of course, it is run by a battery, and the harder they work, the quicker the batteries get drained. So if you have to complete them within a limited time
  • Cordless grinders do not have wires dragging behind them, however, you have to carry two or three batteries depending on the intensity of the work and a quick charger if you don’t want to get stop in the middle of work.
  • Another disadvantage is, cordless grinder price is higher than the chorded one. Price definitely matters when you have a limited budget.

Corded Grinder

Corded grinders need a reliable power source to operate. Since these models have cords and rely on a power source they can run for unlimited time, all you need is a reliable source to supply power. If you want to use a cordless grinder for regular use for minor work then it’s better to choose one with a small disc.

APM is an important factor for the corded grinder. One 4 or 4.5-inch angle grinder that used mostly for DIY needs roughly rated at 6-7 amp which can up go up while a 7-inch grinder is rated at 13 amp, however, neither of these two draws the exact amp while operating. It is just the amount of amp they are rated at.

5-6 amp is normal for a mid-range corded angle grinder, but it can go up to 11 amp and some larger models can reach up to 14 amps. Since standard electrical outlets provide 15 amps some bigger industrial grinders use horsepower instead.

Advantage

  • Corded angle grinders are powered by electricity so you don’t have to rely on a battery. Its unlimited run time is suitable for continuous work and heavy-duty.
  • Corded grinders are available in larger sizes which makes them suitable to cut harder and thicker material.
  • Corded grinders are less in price so it is more affordable than a cordless one
  • Cordless grinders are robust and tend to less overheat which makes them more durable in the long run.

Disadvantage

  • The main disadvantage of corded grinders is they are least portable
  • Because of the limited length of the cord, they can’t go too far from the power source. If you want to take it further you will need extensions.

Which Angle Grinder Should You Buy?

From my point of view, both cordless and corded grinders are best in their own field and have some advantages as well disadvantage. Now if your mind is racing between corded or cordless then my suggestion is to think about your budget and check the review on the top angle grinder available in the market.

Remember cordless angles are not a budget-friendly power tool that you can buy now and then or change models whenever you want. If you have a strict budget and you want an angle grinder to perform some less intense DIY job around your house then I would suggest ignoring the cordless option and opt for a corded one.

If you have financial freedom and the ability to get a cordless angle grinder then you can definitely go for one. However, the arrival of a new model might make yours one “bit” outdated.

Science and technology are improving continuously and we can hope very soon they will bring some batteries that will be able to replace the cord of this power tool and provide use unlimited run time just corded grinders. But till then we have to wait and buy this type of tool according to our budget and choice.

Which Angle Grinder is Beginner-Friendly?

Both corded and cordless angle grinder is a beginner-friendly power tool. All you have to do is following some rules. An angle grinder can ensure that the welding job go well but without following these rules not only a novice, professional can also make blunders

Match Disc RPM with Tool RPM: the disc’s rpm is usually written on the blotter paper. Before placing it on the tool check it with the tool RPM. If the tool has a higher RPM the disc will go down soon and can even explode.

Check for Cracks: check if there is any crack on the disc before starting the work.

Balance the Disc: to get the best result the disc has to be flat on its face and sharp.  So make sure the grinding disc is well balanced.

Use the Correct Metal: for different metals, there are different grinding metals. So use the correct disc for ferrous and nonferrous metals. Because if you use a nonferrous disc on ferrous metal the disc will go down quickly. On the other hand, a ferrous disc on nonferrous metal can clog the disc, create a glaze and frictional heat can explode the glazed disc.

Don’t Use a Small Disc

Do Not Wear Gloves: welding gloves the important but not during the time you are using an angle grinder. Gloves can get caught in the disc and bring the holding hand with it.

Do Not Use Flammable Materials: if you wear any PPE during using a grinder make sure it is not made of any kind of flammable materials because the sparks create from the angle grinder can create problems however if you are using correct PPE in a well-ventilated space, sparks are not something to worry about.

Depending on Size Angle Grinder can be Divided into Three Types

Small: small grinders are typically suitable for 7 inches or less than 7 inches disc although most commonly used sizes are 4” and 4 ½, however, some particular versions are available with the capacity of 3” discs. The small grinder is ideal for a range of cutting and grinding purposes and is featured for a variety of angle grinders.

Medium: medium angle grinders have the capacity to feature discs with 7 inches diameter. Usually, medium sized angle grinders have motors with a capacity of 3 HP and are corded. A medium-size grinder can take a substantial cut and scan a considerable surface in one pass.

Large: 7 to 9 inches discs are categorized for large angle grinders. Like medium grinders, large grinders are also corded and connected motors have the capacity of 5 HP.

Closing Thought

Well, I think you know all the advantages, disadvantages of cordless and corded angle grinders as well as the precaution you should follow. Now if you are completely new about operating an angle grinder it’s better to go with a cheaper one, however, if it’s all about maximizing productivity then you can buy the cordless grinder. In the end, I will just say, you are going to operate a power tool. If you are confident enough take some professional help for safety.

John Boson
john-boson

Sup? This is John Boson signing in from my very own Garage and Woodworking station here! I hate to introduce myself as an expert, rather I am more of a person who loves to share the knowledge for people's interest. Ping me at admin@woodworkingarena.com to let me know if my job on this website has helped you or not. Also, you can request for my honest review or a piece on any know-how topic for what I will try my best. Cheers! Signing out!

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