Diamond Blade Buying Guide
With all of the different saw blades available on the market today, it can be overwhelming when purchasing a new blade. To get the quality of cut you expect with the best performance from your saw, it is important to have the most appropriate blade for the project at hand.
Diamond saw blades come in a wide range of sizes, bond types, and uses with quality and performance that can vary dramatically from blade to blade. Whether you have a tile saw, masonry saw, concrete saw, or other type of saw, selecting the right blade will help you get the job done right.
Segmented, Continuous Rim and Turbo Blades
Diamond blades are available with different rim or edge configurations including
segmented, continuous, and turbo with the type of rim affecting how the blade cuts. The segments or rim are fixed to the blade through the process of brazing, laser welding, or sintering.
Segmented blades typically have
medium to hard bonds for a range of wet and dry cutting applications. While these blades can offer a relatively smooth cut with a fast cutting speed, chipping may still occur. They are durable and have a long blade life compared to other blades.
They are ideal for cutting marble and granite slabs, concrete, asphalt, brick, block, and other building materials. They are available in a wide selection of diameters from small to large and particularly dominate the 12” diameter and larger market. These blades are commonly used with masonry saws, concrete saws, and circular saws.
The spaces of air that separate the segments are called gullets. The gullets are there to improve air flow, dissipate heat, and remove slurry from the cut, helping to maintain the blade’s cutting performance. The size and shape of the gullets vary from blade to blade and will depend on the type of material the blade designed to cut.
For example, blades for cutting asphalt tend to have wider, U-shaped gullets while blades for concrete tend to have narrower, U-shaped gullets. The more abrasive the material, the wider the slot should be to allow for better heat dissipation. Other gullet shapes include keyhole, teardrop, and angled. Segmented diamond blades with narrow slots are generally for marble and granite while keyhole shaped slot blades tend to be for general purpose.
Continuous Rim Blades
Continuous rim blades have
softer bonds for cutting hard materials such as tile, porcelain, granite, stone, glass, and other materials that can chip easily. These blades don’t have individual segments but instead have a solid, continuous rim or edge. Most continuous rim blades are designed for wet cutting applications, providing the smoothest, chip free cuts.
These blades are most commonly available in 4” to 14” diameters. The smaller, 4” to 5” diameter blades are often used in hand-held grinders while the larger sizes are often used with circular saws and tile saws.
There are also variations of continuous rim blades. The J-slot design is one variation that has J-slots around the edge of the blade to help dissipate heat for increased durability, extended blade life, and faster cutting speeds. Additionally, there are J-slot continuous rim blades available for dry cutting applications.
Turbo blades typically have
soft to medium bonds for a variety of general purpose to specific cutting applications. Turbo blades feature a continuous rim with an edge that is serrated. This serrated edge is designed to the give the blade faster cutting speeds while maintaining a smooth cut, combining the best qualities from both segmented and continuous rim blades.
These blades are typically available in sizes that range from 4” to 12” diameters. They can be used in grinders, circular saws, and tile saws to cut a variety of materials including tile, stone, marble, granite, masonry, and other building materials. Blades are available for both wet and dry cutting applications.
Both segmented and continuous rim diamond blades use powdered metals to hold the diamonds in place. The bond strength will
determine the rate at which the diamonds are exposed as the blade is used.
bond strengths can be soft, medium, or hard with the diamonds becoming exposed more quickly the softer the bond.
The bond strength is one of the key factors in determining what material the diamond blade is designed to cut. In order to get the best performance from you blade, it is important to choose a blade with the appropriate bond hardness for the material being cut.
Using a blade with a bond matrix that is too soft for the material being will result in faster wear and shorter blade life because the diamonds will be released faster than needed.
However, using a blade with a bond strength that is too hard for the material will result in much slower cutting speeds and will require more frequent blade dressings in order to expose the next layer of diamond to maintain the blade’s cutting capabilities. Eventually, glazing of the blade may occur as the blade stops cutting all together.
In general, for
hard, dense materials, a diamond blade with a softer bond is ideal because new diamonds are more easily exposed, allowing for better cutting performance. For example, when cutting porcelain tile, a blade with a soft bond will allow new diamonds to be more readily exposed, allowing optimum cutting performance to be maintained.
Softer, more porous materials like asphalt, green concrete, and sandstone tend to be more abrasive, wearing soft-bonded blades out more quickly. Hard-bonded diamond blades are able to withstand the abrasiveness of soft materials, proving to be more durable and long-lasting.
Diamond Grit Size
The diamond grit size, or
diameter of the diamond particles, plays a significant role in quality of the cut. The surface finish quality, smoothness, and amount of chipping are all affected by the diamond grit size. The finer the diamond grit, the smoother the cut will be and the rougher the diamond grit, the coarser the resulting cut. Coarse diamond grits are frequently used where a smooth finish and chipping is not a concern.
The diamond grit size also plays a role in the cutting speed. Because coarse diamond grit size has larger diamond particles than finer grit, the diamond particles are able to remove material more quickly, producing faster cutting speeds. A blade with a grit size appropriate for the material being cut will provide an acceptable finish at the best cutting speed.
Coarse diamond grit (#20 - #60) is often used for masonry, concrete, and natural stone while medium diamond grit (#80 - #220) is frequently ideal for ceramic, porcelain, glass, and other brittle materials. Fine diamond grit (#240 - #400) is used for extremely smooth cutting, polishing, and grinding. Some blades may also have a combination of coarse and fine grit sizes that will allow for faster cutting speeds while maintaining smooth and chip free cuts.
influences the cutting proficiency of diamond blades. The bond type and diamond grit size will both affect the diamond concentration. Having an appropriate diamond concentration will allow for the maximum use of the diamonds and bond. Having diamond concentrations too high for the material being cut can result in diamonds falling off the blade prematurely. Conversely, having diamond concentration too low can result in reduced cutting proficiency.
Diamond concentration typically ranges from 25% to 75%. In general, as the diamond concentration increases, the blade’s cutting efficiency and sharpness decrease. Higher diamond concentrations will decrease the impact of each individual diamond particle, reducing the cutting efficiency but also extending the blade’s life.
Whether a blade is sintered, electroplated, or resin bonded will affect the blade’s capacity for holding diamonds. When the holding strength of the bond is strong, the diamond concentration can also be higher. Saws with a lot of horsepower often need a strong blade with a high diamond concentration for blade durability and longevity.
High diamond concentration with a coarse grit is ideal for cutting abrasive materials while low diamond concentration and fine diamond grit it typically good for cutting hard, dense materials, precision cutting, and polishing. For more efficient cutting where smooth cuts are not a concern, blades with low diamond concentration and coarse grit are often popular.