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    Diamond or CBN: Which Grinding Wheel Do I Need?

    Updated: February 21, 2024 Published: September 29, 2022

    Identifying the right grinding wheel can feel overwhelming when there are many technical aspects involved. One of the most important factors in application success centers around choosing the right wheel for the job. When comparing the actual wheels, CBN (Cubic Boron Nitride) and diamond wheels are much the same, however, the actual cutting materials are what differentiates the two.

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    How Diamond Grinding Wheels Stack Up

    The peak performance of a diamond grinding wheel is achieved when grinding non-ferrous materials like carbide, glass, and ceramics. Even though diamond still takes the top spot when it comes to hardness, it isn’t always the best abrasive for the job. Diamond is not well suited for steel or iron because of the intense heat reaction created when carbon and iron collide at high speeds. The grit of a diamond wheel will quickly erode if subjected to ferrous materials. Overall, diamonds are great for almost anything else. They effectively cut through ceramics, sharpen carbide and polish granite.

    If you’re looking to use a grinding wheel on specialty materials, diamond wheels are the go-to option. Here are a few advantages to consider:

    A Unique Edge…

    The distinctive makeup of a diamond is what contributes to its superior hardness. Diamond can take rough treatment, while still providing a fine cutting edge. Even though diamond appears to be fragile, it is still considered to be the hardest substance. A diamond grinding wheel can come in many different bonds, each one having advantages that distinguish the wheel itself and its applications.

    Quality of finish

    Without the correct grinding wheel, a top-notch finish is almost impossible to obtain. Many factors go into the machining process, leaving room for imperfections if not done correctly at every phase.
    The use of a diamond superabrasive wheel is well-liked because of its precision, long life, and multiple application uses.


    Two factors set diamond grinding wheels apart from other abrasives: strength and longevity. While the cost of a diamond wheel may be more expensive than a conventional grit wheel, the extended life of a diamond wheel will recover that extra investment quickly. The bond of the diamond wheel can be adjusted to fit your unique needs, therefore extending the wheel's life.

    When are CBN Wheels Better?

    When working with ferrous (iron-rich) materials, CBN is the superabrasive of choice. CBN is a highly durable, synthetic abrasive mineral. This type of grinding wheel works best with steel or cast iron applications. CBN doesn’t react as strongly to heat, making it the preferred choice for “heated situations”. Because of this, CBN wheels can be used on ferrous materials at high speeds without affecting the life of the wheel.

    The Bottom Line

    Diamond wheels are the hardest; but certainly not heat’s best friend. If working with a ferrous material, choose CBN grinding wheels to avoid the chemical reaction that will quickly wear the diamond.

    In the end, superabrasive wheels are not “one-size-fits-all”. Each industry requires its own type of wheel to create the desired result based on the material being ground. Identifying the best wheel for the job involves identifying the materials you want to work with and what result you’re looking for.

    Based on this information, we can assist you in choosing the type of wheel that is most efficient for your company. Our application engineers are standing by to give you the advice you need to reach your grinding goals. We can be reached by phone or email to answer your questions.


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