How to Use an Angle Grinder to Cut Metal

When you know how to cut bars, rods and bolts using an angle grinder, you can finish plenty of projects. These can include fences, pipe systems, and window grills, among others. Your effective cutting skills will also be useful in grinding and finishing jobs.

Preparatory Steps

The first step when working with an angle grinder is worker and workplace safety. Keep in mind that an angle grinder can easily scrape off skin, cut bone, and create projectiles.

When in full revolution, it has a free speed of up to 12,000 revolutions per minute (rpm)! 

These preparatory steps are then a must to ensure operator safety:

  • Unplug the grinder before changing its disc or wheel.
  • Check that the handles are firmly attached.
  • Install the guard even when it seems unnecessary.
  • Ensure that the grinder is in good condition via a thorough visual inspection.

If you’re installing a new disc, you must run it in the angle grinder for at least 30 seconds. You should also wear the complete personal protective equipment (PPE).

You want the best possible protection against dust, debris and noise for your body, ears and eyes. 

Your PPE must then consist of:

  • Safety goggles
  • Dust mask
  • Comfortable clothes with coveralls preferably
  • Ear muffs
  • Steel-toed boots or shoes
  • Tough gloves

But it isn’t just your eyes, ears and body that should be safe from the hazards of angle grinder use. You should also ensure that your workplace is as safe as possible. You have to clear it of unnecessary objects, liquid spills, and fire hazards.

When you’re in the right attire and your tool and workplace are in order, you can start on the next steps.

Choose the Right Type of Angle Grinder

The most important factor in choosing an angle grinder is the material. You have to determine the type, depth and size of the material to choose the size and kind of disc needed. Manufacturers typically produce the following grinders and discs:

  • 115mm – 4 1/2 inches
  • 125mm – 5 inches
  • 150mm – 6 inches
  • 180mm – 7 inches
  • 230mm – 9 inches

If you’re planning to cut bars, rods and bolts for a DIY project, you can consider the 115 mm discs. These are suitable for a wide range of DIY jobs, such as cutting reinforcing bars.

But if you’re planning heavier work, the 230 mm discs are the better choices. You can use these discs in cutting steel pipes and I-beams with larger diameters. You have to be more careful in using larger discs because of their higher torques.

You should also consider the pros and cons of each type of angle grinder based on power source. An electric angle grinder offers higher power, as much as 2,000 watts.

A petrol grinder can be used for cutting metal but it’s not recommended for grinding. A compressed air grinder is suitable for industrial applications.

Tip: A 115 mm corded angle grinder will be more than adequate for general DIY applications. But a 230 mm grinder with compressed air power should be used for industrial jobs.

Choose the Right Angle Grinder Disc

Discs are manufactured for specific purposes. Cutting discs for cutting; grinding discs for grinding; and polishing discs for finishing work. You must never use a grinding disc for cutting lest you end up with undesirable injuries and results.

Tip: Look at the disc’s label. It should be labeled either “metal” or “stone”. The material for cutting should match the label on the disc. You can actually cut metal with a stone cutting disc. But the disc will break up resulting in flying debris, which can cause harm to yourself and others.

Effective Steps in Cutting with an Angle Grinder

Now that you have chosen the right angle grinder, it’s time to use it. Keep these tips in mind for safe and effective use of the power tool.

1. Check That the Grinder’s Guard Is Securely Attached

The guard should always be between you and the rotating disc. You can adjust it but don’t remove it while using the angle grinder. You should also cut with the blade’s open section facing away from your face and body.

2. Prop the Bar, Rod or Bolt

The material for cutting should be securely propped against a solid object. The long side of the bar should stay put after cutting while the short side drops away.

3. Make the Cut

Turn on the angle grinder. Let the disc reach its highest speed before putting it into direct contact with the material. Drop the wheel through the material while applying a consistent pressure.

Let the weight of the grinder perform most of the work. If you’re placing excessive pressure on the material, you can ruin it. Let the short end of the bar drop away from the long end.

You should be aware of the spark flow and noise from the grinder. If you observe anything unusual, you’re probably exerting too little or too much pressure.

Final Words

Cutting bars, rods and bolts using an angel grinder is among the easiest and fastest jobs. But you must still adopt safe and effective measures for best results. You can easily cut through the metal with the right disc and technique, too.

Of course, you can also use a hacksaw blade for cutting bars, rods and bolts. But the largely manual process will take more time and energy so it isn’t recommended. Get your angle grinder, put on your PPE, and start cutting through metal with ease.

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top