Composite pavement is the hardest duty a saw blade sees: abrasive asphalt on top, hard concrete underneath, and a blade that has to handle both without being ideal for either. The MK Diamond MK-615W in 14-inch diameter with a .375 kerf is a premium-grade wet blade MK rates as best for asphalt over concrete, in the widest kerf it offers at this diameter.
Built for
- Cut through asphalt overlay into the concrete base below in one pass
- Widen existing joints to a sealant reservoir in composite pavement
- Saw patch boxes and repair cuts in overlaid roadway and parking lots
- Run wet on walk-behind saws in the 8 to 20 hp class
The 3/8-inch kerf is the point of this part number. At .375 it is the widest MK builds in the 14-inch MK-615W, and it is chosen when the cut has to be wide - opening a joint to hold sealant and backer rod, or making a removal cut with enough clearance to lift the section out. The thinner blades in the same range, down to .110, cut faster and cost less to run, so the wide kerf is a deliberate choice rather than a default.
MK rates the MK-615W as best for asphalt over concrete and does not recommend it for plain asphalt, where the MK-705W or MK-710W belongs. That distinction matters: a blade bonded for composite work will not give you the life you expect in straight asphalt, and an asphalt blade will wear out quickly once it reaches the concrete base.
Asphalt is softer than concrete but far more abrasive, and it goes viscous as it heats. That combination is what kills blades: the slurry running down the cut erodes the steel core just under the segments until the segments let go, a failure called undercutting. Running wet keeps the core and the bond cool and flushes that slurry out instead of letting it grind away at the blade. Two habits extend life more than anything else - do not bury the blade to the flange, and do not let it drop into the sub-base, where loose material wears segments fast.
Specifications
- Manufacturer: MK Diamond
- Model: MK-615W
- Part number: 150144
- Grade: Premium
- Material: Asphalt over concrete
- Diameter: 14 inches (356mm)
- Width (kerf): .375 inches
- Arbor: 1 inch
- Segment height: 10mm
- Horsepower range: 8 - 20 hp
- Bond: Laser welded
- Cutting method: Wet only
Frequently asked questions
What is the difference between an asphalt blade and an asphalt-over-concrete blade?
Bond. Asphalt is abrasive and needs a bond that resists wear; concrete is hard and needs a bond that lets diamonds break free and stay sharp. An asphalt-over-concrete blade such as the MK-615W is bonded to handle both layers. MK does not recommend it for plain asphalt, and does not recommend its asphalt blades for composite pavement.
Why choose the .375 kerf over a thinner blade?
Because the cut needs to be wide. A 3/8-inch kerf opens a joint wide enough to take sealant and backer rod, or gives clearance for a removal cut, in a single pass. If you only need to score or relieve stress, a thinner blade in the same range cuts faster and costs less to run.
How does the MK-615W compare to the MK-625W?
MK rates both as best for asphalt over concrete. The MK-625W range runs to a larger maximum diameter, up to 36 inches against 30 inches for the MK-615W, so the choice usually comes down to the diameter and kerf you need rather than a difference in rating.
Does it have to be run wet?
Yes. Water cools the core and bond and flushes slurry out of the cut. That is what prevents undercutting, where slurry erodes the steel core beneath the segments until they break away.
Discount Cleaning Products is an authorized MK Diamond dealer. Our US-based team can help you match blade diameter, kerf width and bond to the saw and the material you are actually cutting, so you are not guessing at a part number. If you are not sure which blade in the range fits your saw, contact us with your saw model and horsepower and we will point you to the right one.
