diamond blade basics Diamond blades contain industrial-grade diamond embedded in segments or rims on their cutting edge. As the blade is used, the abrasive qualities of the material being cut (such as concrete) wears down the segment. Diamond crystals either get crushed or let loose as the metal matrix gets worn away, exposing new diamonds to continue the cutting. The abrasive quality of the material being cut is a large factor in choosing the correct blade for a job. Harder, less abrasive materials such as cured concrete require a blade with a softer metal mix to ensure adequate erosion of the segment brings new diamond to the surface at an optimum rate. Soft, abrasive materials such as green concrete and asphalt tend to wear down segments faster. Therefore, segments with a harder, more wear-resistant metal mix in the segment, provide longer blade life and overall better performance. Abrasive materials tend to erode the metal core, or center, of diamond blades causing undercutting. Undercutting tends to be concentrated on part of the core that attaches to the segment. If undercutting is excessive, it can cause segment loss and damage the blade. NED offers 2 types of undercut protection which reduce abrasive slurry accumulation beneath the segments to provide extended blade life. Segments come in different heights. The total segment height is not as important as the diamond depth – the portion of the segment that contains diamonds. The diamond depth combined with diamond concentration and quality determines the overall performance value of the blade. The accompanying chart shows the effect different variables have on a diamond blade cutting speed and blade life.
WHAT TO CONSIDER WHEN CHOOSING A DIAMOND BLADE
Variables
Change Result Cutting Blade Speed Life
Segment Bond Hardness
Harder Slower Longer Softer Faster Shorter
Segment Width
Thinner Faster Shorter Thicker Slower Longer
Material Hardness
Harder Slower Longer Softer Faster Shorter
What is the cutting method? Wet or Dry?
Material Abrasiveness
More Faster Shorter Less Slower Longer
What kind of equipment is being used?
Material Steel Reinforcing
Less Faster Longer More Slower Shorter
Material Aggregate Size
Smaller Faster Shorter Larger Slower Longer
Horsepower
Lower Slower Longer Higher Faster Shorter
Blade Speed RPM
Lower Faster Shorter Higher Slower Longer
Water Volume
Lower Faster Shorter Higher Slower Longer
Cutting Pressure
Lower Slower Shorter Higher Faster Longer
Cutting Depth
Shallow Faster Longer Deep Slower Shorter
What is the material?
Brick? Block? Combination of Brick and Block? Green Concrete? Cured Concrete? Asphalt?
High speed hand held saw? Masonry table type saw? Walk behind saw? (low or high H.P.) Hand held power tool? How deep is the cut?
Use proper blade diameter for depth required. (remember, a 5” cut requires a 14” blade.) How big is the job?
Higher quality blades are more economical to use.
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DIAMOND BLADE CUTTING PERFORMANCE VARIABLES
specifying diamond blade
HARDNESS
CRITICALLY HARD
HARD
8000 PSI (Power Plants)
6000 - 8000 PSI (Bridges & Airport Runways) River Rock, Quartz, Some Granite, Schist
Flint, Chert, AGGREGATE Basalt, Trap Rock, TYPE Quartz AGGREGATE SIZES
+1 1/2” Sieved Gravel Round (Low Abrasion)
SAND
Heavy • #4 rebar (1/2”) • #5 rebar (5/8”) • Multi mat wire mesh
STEEL REINFORCING BLADE OR CORE BIT BOND HARDNESS SELECTION