How Does a Diamond Blade Cut?

So you have a diamond blade, it cuts stuff, and it cuts it well. That’s good enough for most people. Are you one of those rare and troublesome folk, though, who’s wondered how it works? If you are, then this article was written for you.


How Most Diamond Blades Cut

Most diamond blades have cutting segments that are made up of diamond grit suspended in some kind of metal matrix or “bond”. Some of these diamonds are on the surface, but most are buried within the cutting segment’s bond.

It’s important to remember two things about these surface diamonds. First, they grind instead of cut, an important distinction that we’ll get back to in a moment. Second, they do all the cutting work on your blade. All the bond does is hold these surface diamonds in place, while the diamonds buried within the bond do, well, nothing.

Now, diamonds are one of the hardest substances on Earth (they lost the top spot in 2009 to two other materials), but even they’ll wear down and stop cutting on a diamond blade.

This is where the bond comes into play. Ideally, the bond will wear away just fast enough to shed worn surface diamonds and expose fresh, sharp diamonds buried deeper in the cutting segment. This means that you shouldn’t notice any change in your cutting speed as your blade wears down.


Problems with Most Diamond Blades

Of course, nothing happens “ideally”. Your blade bond won’t exactly match the materials that you cut. It will either be too soft or too hard.

If your bond is too soft, your blade will wear down faster than normal. This means that you’ll have to replace your blade more often, which in turn means that you’ll spend more than you should on replacement diamond blades.

If your bond is too hard, on the other hand, the surface diamonds – the diamonds that do all of your blade’s cutting – will wear down faster than the bond. This can lead to your blade “glazing over”, where the surface diamonds wear down completely before they can be shed. When this happens, your blade will cut slower and then refuse to cut.

Worn and glazed blades are both dangerous, and for similar reasons.

Soft-bonded blades can have their cutting segments “undercut” in abrasive materials, like asphalt, green concrete, and sandstone, especially if they don’t have undercut protection. Glazed blades, on the other hand, hammer the material instead of cutting it, which increases friction and overheats the welds holding the cutting segments. Undercutting and overheating can both break cutting segments off the blade, injuring or even killing the saw operator.

To avoid broken segments, you should, as a rule of thumb, choose harder bonds when cutting softer materials and softer bonds when cutting harder materials. This isn’t a perfect rule, though, and could force you to change blades whenever you change the material that you’re cutting.


Advantages of Vacuum-Brazed Blades

Vacuum-brazed blades like the Ductile Iron Safety Blade and Fire Rescue Safety Blade avoid these problems because they have their diamonds vacuum-brazed onto the surfaces of their cutting segments. None of the diamonds are buried inside a bond. Instead, they’re all on the surface, ready to cut.

This means that you don’t have to match up the bond of a vacuum-brazed blade to the hardness of your material. Vacuum-brazed blades cut almost everything, including metals, asphalt, stone, and concrete, and are more versatile than other diamond blades.


Works Cited

“Our Vacuum Brazing Process Gives You a More Versatile Blade That Can Tackle Any Cutting Job.” Desert Diamond Industries Product Catalog. N.p.: n.p., n.d. 27. Print.

“Frequently Asked Questions.” Desert Diamond Industries. Desert Diamond Industries, n.d. Web. 27 Aug. 2013.

“Frequently Asked Questions – Why Is My Diamond Blade’s Bond Important? How Does It Affect What I Can Cut and My Cutting Speed?” Desert Diamond Industries’ Blog. Desert Diamond Industries, 12 Dec. 2012. Web. 27 Aug. 2013.

“Q. My diamond blade isn’t cutting. Is it defective?” Desert Diamond Industries’ Blog. Desert Diamond Industries, 29 Nov. 2012. Web. 27 Aug. 2013.

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