Diamond blades are the standard for cutting concrete, stone, tile, and asphalt. But different blades are designed for specific materials and applications. Therefore, we’ve created the ultimate guide to choosing a diamond blade.
There are dozens of considerations to contend with when choosing a diamond blade for a handheld circular saw or a walk-behind saw. We’ve included what we think are the most important factors below.
It may seem odd to start with cost right at the top, but if you have a tight or rigid budget, it’s the first think you should think about. Be realistic about your price range, but also decide if it’s time to splurge on a high-quality blade that will offer the best performance.
The highest quality diamond saw blades may reflect their quality in their price, but not always. And the price won’t necessarily be a good criterion on which to base your decision. Don’t spend hard-earned money on the wrong type of saw blade just because it costs less.
Horsepower and RPM
Saws are rated by their horsepower and revolutions per minute (RPM). Make sure the blade you choose is rated for the horsepower and RPM of the saw you will use it with. Running the blade at the wrong speed can cause it to warp and wobble, and it will wear excessively as a result.
Low performance blades run well on low horsepower, while high performance blades can thrive with higher horsepower saws.
Materials Being Cut
This is perhaps the most important consideration when choosing a diamond blade. Diamond blades are made for specific materials based on the materials’ hardness.
The material you cut will fall into one of four categories: soft, medium to soft, medium to hard, and hard. Different blades work better on different materials.
The reason a general use or universal blade might not be the best choice if you use your saw frequently lies in the bond that adheres the diamonds to the blade. A soft bond is, paradoxically, better for hard materials, while a hard bond is best for softer materials.
This is because the bond will wear away as you use the saw, exposing the next layer of diamonds fused to the blade. Diamonds are typically affixed to a blade by one of four processes:
- Electroplating: Blades made through an electroplating process are single layer, with a greater concentration of diamond crystals on the surface. The diamond attaches to the blade in an electroplating tank, where the negatively charged core is put into a tank with the positively charged diamond crystals. The two attract, and the diamonds get “tacked” to the plate. Then nickel is added as a follow-up, to secure the diamonds even more tightly in place. The single layer surface of electroplated blades is dense with sharp, pointed diamond crystals, and are best for softer materials like plastics, fiberglass, and soft stone. The electroplated surface is sharp but can be fragile.
- Sintering: In a sintering process, synthetic diamond crystals are mixed with a metallic powder, and the substance is heated to a temperature just above or below the metal’s melting point. This causes the diamond crystals to become affixed to or embedded in the metal, layer by layer. Sintering is appropriate for blades that cut hard materials because it will wear away at the correct rate to expose new, sharp diamond particles that will continue to grind away the material being cut.
- Vacuum Brazing: Vacuum ovens remove oxygen and heat oxide-free nickel at high but carefully controlled temperatures to affix diamonds to the core surface. The result, like electroplated saw blades, is a surface that is dense with a high concentration of diamond particles. The difference between vacuum brazed and electroplate blades is that the diamond crystals on the vacuum brazed blade are more rounded and duller, to tolerate the extremely high temperatures required in the vacuum brazing process. The slightly less aggressive surface of a vacuum brazed blade is good for some metals, and for soft stone like limestone and marble, where the electroplated blade might be too fragile.
- Laser welding: This method yields the strongest bond between diamonds and the saw core and segments. Coupled with thicker, tensioned, and heat-treated steel cores, laser welded diamond blades work well with high-horsepower, deeper penetrating, wet-cutting methods used on hard materials. The laser-welded surface minimizes drag, and a tensioned core helps retain flatness at high RPMs.
Segmented, Continuous, or Turbo Blades
You’ll see that some diamond blades have edges that have sections with space in between. These are called segmented blades. The space between the segments aids cooling and helps with expelling dust. Segmented blades can create rougher cuts and they can cause chipping. Segmented blades are effective on concrete, granite, marble, and asphalt.
Continuous blades don’t have segments—they look like smooth discs. They’re good for wet cutting and materials that are prone to chipping, like tile, glass, and some types of stone. Use a continuous blade on hard materials that require a refined finish.
Turbo blades are continuous blades with a serrated edge. They have a soft bond suitable for very hard materials. Like regular continuous blades, they produce less shock to the surface, reducing chipping. But unlike ordinary continuous blades, the serration makes them more aggressive to handle extremely hard materials, like granite.
The diameter of the core matters as it affects the depth of the cut and whether the blade is compatible with the saw you’re using. Smaller blades are used in grinders, while larger blades are for hand-held circular saws and tile saws. Diameter is also directly related to the RPM of the saw you use, so be sure you check the RPM tables for both the blade and the saw to ensure they are compatible with each other.
We hope this ultimate guide to choosing a diamond blade is helpful to you in selecting the blade that will work best for the materials you work on. If you have additional questions, please contact us. As diamond blade suppliers, we at Pro Blades Outlet are always ready to help you find the blade you need for the machine you use, as well as the materials you’ll encounter in your next job.