How to Choose Diamond Saw Blade for Cutting Concrete

Diamond Blade are usually the best choice for making clean, professional concrete cuts. However, in this category, you can find numerous blade options at various price levels. How do you choose the perfect blade for the job at hand? To get the best cutting performance, follow this saw blades buying guide before purchasing your concrete saw blades.

If you understand how a diamond blade works, choosing a blade with the right characteristics and cutting quality for your needs will be much easier. Here are the four basic blade components:

  1. The steel core, a precision-engineered steel disk with a segmented rim, the diamonds will hold on the segmented rim. 
  2. The synthetic diamond crystals, the  cutting teeth that grind through the concrete, asphalt and other target materials.
  3. The weld, which attaches the cutting segments to the steel core.

Each section of the surface exposed diamond is cut, and when the blade is rotated at a high speed, the material is cut by grinding. When the surface diamond becomes dull due to use, the carcass begins to fall off, releasing the worn diamond crystals, exposing new, sharp diamonds embedded in the carcass. The most important fact to be aware of is that the hardness of the blade base determines the speed at which the blade wears. The basic rules here: Diamond blades are used to cut soft, abrasive materials (such as uncured, green concrete) that should have a hard metal bond so that the exposed diamonds are fully utilized before they fall off. Conversely, blades used to cut hard, non-ground concrete should have a soft adhesive to make it easier to erode the substrate, which will ensure that new, sharp diamonds are exposed when you need them.

Wet Cutting  vs. Dry Cutting 

Wet cutting or dry cutting depends on your preferences and job requirements. Dry Cutting eliminates clutter in wet pulp and requires water tanks and hoses for the saw. On the other hand, the use of wet blade can reduce dust, but must contain or clean the pulp. For Indoor operations that require the work area to be kept dry, dry cutting blades and compatible saws may be your only option. The main difference between wet and dry blades is welding.

The dry cutting blade has a heat-resistant section weld and does not require water cooling. They are commonly used for intermittent cutting and for hand-held low-horsepower saws. If you are sawing decorative pattern lines in concrete, dry cutting blades are usually the best choice for clear, clean cuts.

These cosmetic cuts are usually only 1 / 16th to 1 / 4th of an inch deep and do not control the joint. Wet-cutting blades are often used with hand saws to cut joints in the hardened concrete plane, as water cooling allows for deeper cutting. Although most dry cutting blades can be used with water, do not use dry cutting blades. Continue Cooling the blades with water at all times to avoid segment loss and blade warping.

choose the Right Diamond Blades according to the type of Concrete

For maximum cutting speed and blade life, you should match the blade to the material you are cutting as closely as possible. The properties of concrete you need to know include compressive strength, size and hardness of aggregates, and type of sand.

Blade Manufacturers rate the compressive strength of concrete to be 3000 PSI or less, soft material and concrete to be stronger than 6000 PSI hard material. Therefore, you should use a blade with a hard bond to cut low strength concrete, and a blade with a soft bond to cut high PSI concrete. Similarly, hard aggregates (such as trap rock, basalt, and quartz) quickly passivate diamond grains, so using a blade with a softer bond can expose new diamonds as needed.

The size of aggregate in concrete mainly affects the performance of blade. When cutting larger aggregates (3 / 4″and above) , the blades cut and wear more slowly.”. PEA Gravel (less than 3 / 8 in) is easier to cut but the blade wears out faster.

The type of sand determines the Abrasiveness of concrete. Sharp sand is the most abrasive, while round sand is the least. To determine the sharpness of sand, you need to know where it came from. Crushed or riverbank sand is usually sharp, while river sand is round and non-abrasive. The greater the abrasive nature of the sand, the harder the bond is required.

What if you have to cut multiple kinds of concrete? As a general rule, manufacturers recommend selecting blades based on the material you use most often or the material whose performance is most important to the top blade. Most diamond blades can cut a range of materials.

Choosing the Right Time to start cutting.

If you want to place new concrete, you can choose to cut the control joint the day after the concrete is still green (about 1-2 hours after completion) or the day after the concrete has hardened. The time of cutting will determine the type of blade you choose. Some decorative concrete contractors prefer to cut concrete while it is still green because it minimizes ugly random cracking (especially in warm weather, when concrete hydrates faster) And allows for a shallower seam depth of one inch or less. However, green concrete is softer and more resistant to abrasion than the same concrete in its cured state. That’s because the sand in the mixture has not yet bonded to the mortar and it acts as an abrasive. The blade manufacturer supplies hard diamond blades specifically for cutting green concrete.

Choose Concrete Blades according to your cutting Equipment

Diamond saw blade manufacturers provide charts with recommended operating speeds and maximum safe blade operating speeds. You will also find this information on the blade itself. Always match the blade to the speed range of the saw. Operating the blades at speeds lower than the recommended speeds will reduce their cutting life and performance. Exceeding the maximum speed rating of the blade may damage the blade and may cause injury to the saw operator. Other considerations: Blades designed for wet use must be operated with a saw that provides a continuous water supply to cool the blades. Most of the blades used to cut green concrete are designed for special early entry saws that minimize loosening and flaking of joints. Do not use blades larger than the maximum blade diameter and cutting depth.

Balance between good Performance and low cost

Diamond saw blade manufacturers usually offer diamond blades of  ranges quality and cost levels, from the basic economy to the top-end or professional edition. Often, the key difference between these options is the diamond content, which is the biggest raw material cost at the time of making the blade. Upgrading from a standard blade to a quality blade may increase costs by 18% or more, but you’ll get higher diamond concentration and longer blade life. Basically, you need to decide what is more important: the initial cost of the blade or the total cost of cutting. For smaller cuts, you won’t be exercising the blades a lot, and you can save money by using the economical blades. For large-scale operations or frequent use, in the long run, high-quality blades may actually be cheaper based on the failure of each cutting cost. A good diamond blade is not cheap. Depending on blade diameter, expect to pay hundreds of dollars or more. If it’s not just that you’re willing to invest in the occasional layoff, consider hiring a professional sawing contractor to do the job.

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