When we buy diamond saw blade, we hope it can last as long as possible, but the blade life varies depending on a number of variables. Of course, the most key factor is the quality. The blade quality should be superior, and then we can talk about its lifespan.
Before we know how to use the saw blade as long as possible, we should know the factors that affect the longevity. Basically, these factors can be classified into 3 categories.
I) Blade Itself
How can we define the diamond concentration? There is standard in diamond tool industry. The diamond concentration will be 100%, if there is 4.4 karat diamond in one cubic centimeter of segment, if there is 3.3karat diamond, the concentration is 75%.
Except for the weight concentration, there is volume concentration as well. The diamond concentration will be 100% if the diamond volume occupies 1/4 of the total volume of segment. So, increase the diamond concentration, the blade life can be lengthened.
30/40 to 60/80, this is the popular grit size range for diamond saw blade. The blade will have longer life with fine diamond grit. However, we have to consider the material hardness before choosing the grit size. If the blade is to cut granite, it is better to choose 40/50 or 60/70, while if the material is concrete, 30/40 is better.
The bond is composed of several different metal powders; it is used to wrap the diamond grit. The harder bond, the better resistance to wear. To improve the hardness of the bond, cobalt or tungsten carbide is usually added to the bond.
II) The materials
Cutting a hard material such as concrete requires a different blade than one used to cut a soft, abrasive material such as asphalt. The harder material requires diamonds to be exposed more quickly, and a softer bond to hold the diamonds to the segment.
If the material is hard stone, then choose the fine diamond grit.
III) Cutting Parameters during operation
In practice, the linear speed of blade is confined by the equipments, blade quality and cutting materials. In consideration of the blade lifespan and cutting efficiency, the cutting linear speed should be different according to different material. To cut granite, the optimum linear speed is between 25 to 35 m/s. For high quartz content and difficult cutting granite, remove the blade speed limit is appropriate. cubic boron nitride tiles in the production, the use of smaller diameter diamond saw blade, the line speed can reach 35m / s.
2. Cutting Depth:
Diamond cutting depth is the key parameter in relation to diamond wearing, cutting performance and cutting material. Normally, the cutting depth should be set smaller if the blade linear speed is high. According to the current technology, the cutting depth of the diamond is between 1mm ~ 10mm. Usually with a large diameter saw blade cutting granite blocks, the cutting depth can be controlled within 1mm ~ 2mm between the feed rate should be reduced at the same time. When the linear speed is high, a large cutting depth should be selected.
3. Feeding speed:
The feeding speed affects the cutting efficiency, impact force on blade and the cooling of cutting area. A suitable feeding speed should be set based on the nature of the cutting material. Generally, to cut the soft material, the marble for example, in order to get big cutting depth, the feeding speed can be slower. While, if the material is granite, the feeding speed should be higher, otherwise the diamond grit will be worn out easily. The feeding speed on cutting granite is 9-12m/min.
Tips for longer life
Given these variables, there are still some things we can do to maximize the lifespan of diamond saw blade.
Choose the right blade for the job. There are concrete blades/asphalt blades/granite blades/green concrete blades/ring saw blades, etc. These blades are specially designed for different applications, while general-purpose blades can cover a wide variety of cutting tasks, application-specific blades are engineered with a specific bond to meet the needs of a certain application. They do the best job and will last longer.
So, before choosing the saw blade, it is better to ask yourself the following questions
Follow the instruction on blade. if the blade shows “wet,” then use this blade when wet, it is the common mistake to use wet blade dry. If a wet blade is used in dry condition, it is high possibility that the blade segment will burn up without taking long. But every dry blade can be used wet, in fact the lifespan of dry blade will be longer if water was added during cutting. Also, water will eliminate heat and dust.
Don't bury the blade. Another common mistake is burying the blade all the way to the flange, or forcing the blade through the material being cut.
Forcing the blade through material will damage the saw by increasing the amperage, burning up the motor and overheating the blade, which causes premature wear and damage, Metal in the diamond rim can get so hot that it actually covers the diamonds. Glazing over diamonds on the rim can cause blades to dull and stop cutting, even though there's a lot of life left on the diamond rim of the blade
Don't push too hard. There is operating limit on both equipments and saw blades. Equipment and blade will fail if push too hard. Just follow the recommended rpm.
Install the blade properly. Pay attention to the directional arrows labeled on the blade to ensure the blade is installed properly and spins in the intended direction. The blade will wear out quickly if it is spinning the wrong way.
The pinhole behind the center arbor is also very important on walk behind saw blades, the pinhole on the flange steadies the blade and prevents wobbling.
Be careful in the turns. If you are going to change directions, do remember to switch off the saw machine and lift up the blade. The blade easily get bend and break if the saw machine change directions while the blade is still in the cut.