How to cut metal bolts with an angle grinder

How to Cut a Metal Bolt with Your Angle Grinder

If you need to cut a metal bolt using an angle grinder will get the job done. You can cut a bolt down to the right size with a grinder or trim an exposed bolt that poses a safety risk. Here we will cover how to cut a metal bolt with an angle grinder.

Angle grinders perform great in this task since they use a sturdy diamond disc, have a powerful motor, and are comfortable to hold. No matter your need, an angle grinder will allow you to quickly and easily cut through a bolt with minimal effort.

How to cut a metal bolt with an angle grinder:

There are seven steps to cutting a metal bolt with a grinder:

  1. Use a marker pen to mark the cut line
  2. Add two nuts to the bolt
  3. Clamp the bolt
  4. Put on safety gear
  5. Cut the bolt with your angle grinder
  6. Deburr the cut metal bolt
  7. Reform the thread

Let’s break each step down in detail:

The process of cutting metal bolts with an angle grinder

Step 1: Use a marker pen to mark the cut line

With your Sharpie, make a line on the bolt where you’d like to make your cut. Use your measuring tape to ensure the finished length (after you cut) is what you need.

Step 2: Add two bolts to the bolt

In this step screw two nuts onto the bolt up to the base. Ensure the nuts are tight and close to each other.

The nuts will make it easy to clamp the bolt to the vise. They will also help you in lining the threads once you cut the bolt. This is an important step to put two nuts on FIRST. Otherwise you will have trouble getting the nuts on after cutting, because the threads will be out of alignment.

Step 3: Clamp the bolt

After adding the nuts, clamp the bolt on the vise. Make sure the bolt is tightly secured and easily accessible to make your cut.

Generally, the best position is with the end of the bolt (the part you are cutting off) facing up.

Step 4: Put on safety gear

Ensure you have safety glasses on, at a minimum, to protect yourself from any debris. Hearing protection is also advised.

Step 5: Cut the metal bolt with your angle grinder

After ensuring you have a cutting blade installed on your angle grinder, carefully turn it on. For good results, cut at a flat angle on your cut line to avoid compromising the threads. Without applying force or pressure, cut through the bolt.

This process will take a short time – likely less than a minute. When cutting, direct the tool away from your body. Additionally, hold the handle firmly to prevent the tool from falling.

After cutting the bolt do not hold it directly with bare hands. This will prevent injuries because the bolt gets hot while cutting. Also, make sure to turn off the tool immediately after cutting.

Step 6: Deburr the cut metal bolt

Smooth out the cut end of the bolt using an abrasive pad. This process will smooth the sharp end that might prick your skin.

Step 7: Reform the thread

Now unscrew the added nuts towards the top of the thread to a point where it proves resistance. Use a wrench to back it entirely off the bolt.

This process will re-form the thread, making the bolt usable.

Besides a top-rated angle grinder, there are a few things you will want to have on hand before you begin.

What you need to cut a metal bolt

  • Bolt – the one you need to cut or trim
  • Sharpie pen or marker pen
  • Ruler
  • 2 Nuts
  • Abrasive Pad
  • Wrench
  • Bench vise
  • Angle grinder
  • Cutting disc for angle grinder
  • Safety glasses
  • Ear Protection

A quick note about your cutting disc. Ensure you have the correct disc installed before beginning this process. There is a difference between grinder discs and cutting discs. Cutting discs are less thick than grinder discs, which allow them to cut more effectively.

Now that you understand how to cut a metal bolt with your angle grinder, watch this video to master the process:

Wrapping up

Congratulations, your bolt is now ready for use! The main takeaways to remember in this process are:

  • Use a cutting disc, which is thinner than a grinder disc
  • Use a strong vice grip to hold the metal bolt in place as you use your angle grinder
  • Make sure you place the nuts on prior to cutting the bolt to properly re-thread
  • Use safety gear such as safety glasses and hearing protection

Happy cutting!

Related article: How to Cut Plaster Walls Using Angle Grinder: Guidelines from our Experts