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2 Things to Remember When Cutting Concrete: Aggregate and Speed

By September 29, 2022August 24th, 2023Blog Posts

Diamond blades are ideal tools for cutting through the hardest materials. Take concrete. The right diamond blade from Devour Tools is more than a match for concrete. Still, it’s not smart to recklessly dive into a cutting project without paying attention to the details. Two of the most important details for concrete jobs are aggregate and speed.

Aggregate relates to the actual composition of the concrete where speed refers to the cutting speed of the blade. Though there are a lot of different things that influence blade life and cut quality, none are more important to concrete than aggregate and cutting speed.

Know Your Aggregate

Concrete is a mixture of liquid cement and an aggregate. The aggregate is generally a mixture of fine and coarse particulate materials chosen based on performance. In most concretes, there is one particular material that dominates the aggregate. Some of the more common choices are limestone and quartz.

Harder aggregates require more power and force to cut than their softer counterparts. They also tend to wear on diamond saw blades faster. That’s why we recommend a diamond blade with softer bonds for hard aggregates and a blade with harder bonds for softer aggregates.

The point here is to know the aggregates you are working with before you start cutting. There are tests for measuring hardness, tests you can conduct as long as you know the constituents of the concrete. Here are three options:

  • Los Angeles Abrasion-Loss Test
  • Mohs Scratch Test
  • Shore Hardness Test.

One last thing before we move on: the actual size of the aggregate is as important as its hardness. The larger the size, the more difficult the cutting job will be.

Cutting Speed

Cutting speed is critical inasmuch as diamond saw blades are designed to self-tension during the cutting process. In other words, a typical diamond blade is manufactured with a slight dish shape. It is not flat. It’s designed that way so that the blade flattens out as you cut.

The angle of the dishing is so slight that it’s hard to notice with the naked eye. We are talking tens of thousands of an inch. It’s just enough to allow a blade to flatten out so that it doesn’t distort during the job. But in order for it to properly flatten, the blade needs to turn at optimum speed.

Cuts Can Wander

Speed is critical to concrete cutting because a blade turning too slowly causes the cut to wander. As you try to keep the cut straight, you’re working against the blade. You get a lower quality cut and reduce the life of the blade at the same time.

Like nearly every other brand, Devour blades have the maximum speed printed right on them. That way, there is never any guesswork on your part. Note that maximum speed doesn’t necessarily mean that this is the best speed for every job. This is why it’s important to know your aggregates. You may have to adjust speed to account for harder or softer aggregates of varying sizes.

Experience Helps, Too

Cutting any hard surface with a diamond blade isn’t an exact science. We do our best to make it easy by producing the highest quality blades and giving customers all the information that they need to choose and use our blades properly. You do your best to take care of your blades but still get the job done.

In the end, experience is the best teacher. Over time, you’ll learn the best way to use diamond blades on every job. Just remember to pay attention to aggregate and speed on those concrete jobs.