Asphalt and some paving blocks are very abrasive. A blade designed for these materials must have a hard bond. A blade for brick or hard concrete must have a much softer bond to allow the blade to wear properly. A blade with a bond which is too hard will glaze over, not expose any new diamond and will eventually stop cutting.
Brick and hard concrete are hard to cut and low in abrasiveness. A blade designed for these materials must have a softer bond. However, when a softer bonded blade is used on an abrasive material, this is very destructive to the soft metals in the blade. The result is premature release of exposed diamond and a greatly reduced blade life.
The most common reason for a blade not cutting is usually a misapplication. A loss of cutting speed is often encountered on harder materials which have little or no abrasiveness. A hard bonded blade used on a hard material will not wear properly as it does not wear away at a fast enough rate to keep diamond exposed to allow continuous cutting.
In most applications, water will improve the life of the blade.
The equipment used with diamond blades have specific power ratings. Equipment varies from hand held cut off saws to 65 HP walk behind floor saws. It is therefore essential that the power of your machine is verified prior to selecting a diamond blade.
It is important that the arbor of the product fits correctly on the equipment. Both 20mm and 25.4mm (1 inch) are common arbor sizes for diamond blades. Ensure you check the arbor size of the machine and the blade are compatible.
- The diamond blade is too hard for material.
- The concrete saw is in need of repair.
- The diamond blade is mounted improperly.
- The diamond blade is overheating.
If there is segment loss or cracking of the metal steel core the blade should be removed and returned for analysis. These issues are normally due to misapplication.
Always allow the diamond blade to do the cutting. No force is necessary when the correct blade is specified. The machine used will guide the blade and provide the energy to cut the concrete. There is less fatigue on the operator when the blade does the work.
Undercutting is when the steel core wears faster than the segments due to the fynes of the abrasive material being cut, wearing the core faster than the segment. If the blade continues to be used the core will wear below the segment weld and break away from the core of the diamond blade.
Undercut protection, particularly used on blades for abrasive materials, is provided either by deep segment, hammer segment or slanted segment.
Slow cutting usually occurs when a diamond blade is used to cut a material that is too hard for the segment being used. The hard material wears the exposed diamonds, but the metal matrix holding the diamond grit in place due to its hardness, does not wear proportionately.
The segment then becomes glazed over, overheats, bounces in the material being cut and finally fails to cut, leading to cracks in the core or segment loss.
When this occurs and is noticed before the blade loses its tension, the best solution is to run the diamond blade in a soft abrasive material like a masonry block until the diamonds in the matrix are freshly exposed.
A diamond blade professional should be consulted to help with specifying the correct blade for the material to be cut.
Check the flanges are fitting correctly and that the RPM rating is correct. Always follow the guidelines for proper blade operation and cooling procedures.
Short blade life of a diamond blade usually occurs when a blade is used to cut a material that is soft and abrasive, such as soft sandstone and asphalt. The abrasive material wears the matrix of segment faster exposing and losing more diamond grit at a faster rate than necessary.
Specify the correct diamond blade and choose a blade with a harder bond. Most blades are graded for material types and then additionally graded for quality and durability within those types.