Cutting wheels and cutoff wheels are often treated as interchangeable. They’re thin, they spin fast, and they slice through metal. But using them incorrectly is one of the most common grinder mistakes on the job site—and one of the fastest ways to ruin a tool or cause an injury.

At CEM Industrial Supply, this confusion shows up constantly. Here’s the straight answer.

What Cutoff Wheels Are Designed To Do

Cutoff wheels are built for one job: straight cuts. They are thin, rigid, and designed to be used at a 90-degree angle to the work surface.

Cutoff wheels are best for:

  • Cutting bolts and threaded rod
  • Slicing tubing and pipe
  • Trimming metal stock
  • Making clean, precise cuts

They are not designed for side pressure. Any twisting, prying, or grinding action dramatically increases the risk of wheel failure.

What Cutting Wheels Are Commonly Misused For

Many people refer to any thin wheel as a “cutting wheel,” but that’s where problems start.

Thin wheels used improperly often get:

  • Forced sideways to widen cuts
  • Used for light grinding
  • Bent under pressure

This misuse leads to cracking, wheel breakage, and dangerous failures at speed.

Why Side Pressure Is So Dangerous

Cutoff wheels are engineered to handle radial force, not lateral stress. Side loading causes microscopic fractures that weaken the wheel until it fails.

This is why:

  • Wheels explode without warning
  • Guards get damaged
  • Operators get injured

If the wheel isn’t rated for side grinding, it should never be used that way.

Proper Technique for Longer Wheel Life

To use cutoff wheels safely and effectively:

  • Keep cuts straight
  • Let the wheel cut at its own pace
  • Avoid twisting or levering the grinder
  • Replace wheels early if they show wear or damage

If you need to grind after cutting, switch to a grinding wheel or flap disc. It’s faster and safer.

RPM Ratings Still Apply

Cutoff wheels have maximum RPM ratings just like grinding discs. Running a wheel above its rated speed is a major safety violation and a common cause of failure.

Always verify:

  • Grinder no-load speed
  • Wheel RPM rating
  • Proper wheel diameter

The Bottom Line

Cutoff wheels cut. Grinding wheels grind. Mixing the two causes tool damage, safety risks, and wasted time.

If you’re unsure which wheel is right for your job, CEM Industrial Supply can help you choose the correct wheel—and show you how to use it safely.