Cured concrete is the hardest thing a flat saw is asked to do all week, and the blade is where that job is won or lost. The MK Diamond MK-525 is the top of MK's three cured-concrete grades - the company rates it Best on cured concrete, above the MK-505 and the MK-500 - and it is built for the contractor who would rather buy one blade than replace three. This 12-inch (305mm) version runs a .375-inch kerf on a 1-inch arbor and is the widest of the three 12-inch MK-525 kerfs MK Diamond publishes (.125, .250 and .375). It is the size and width for wide-kerf work where the specified joint or slot is the point of the cut, not just the separation.
Built for
- Full-depth slab sawing on cured concrete for demolition, trenching and slab removal.
- Control-joint and expansion-joint cutting on flatwork that has already gained strength.
- Hard-aggregate mixes with non-abrasive sand, which is the condition MK rates the MK-525 Best in.
- Concrete cutting contractors and municipal crews running walk-behind and self-propelled wet flat saws.
- Rental fleets and shops that want one supreme-grade blade to cover the hard mixes their standard blade gives up on.
Use Cases
The most expensive mistake in concrete sawing is running the wrong blade in the wrong mix, and it rarely announces itself. The blade just gets slow, the operator leans into it, and a day's production disappears into a cut that should have taken an hour. MK Diamond addresses this directly by publishing an application chart rather than a marketing claim: the MK-525 is rated Best on cured concrete, Best on hard aggregate with non-abrasive sand, Best on soft aggregate with abrasive sand and Good on medium-hard aggregate with abrasive sand.
One caution worth reading before you order. MK does not recommend this family - the MK-525 included - for hard aggregate combined with abrasive sand. It also routes medium-hard aggregate with non-abrasive sand to the MK-505 rather than to the MK-525, and soft aggregate with non-abrasive sand to the MK-500. Buying up the grade ladder is not automatically the right answer; matching the bond to the mix is. If you know what your aggregate and sand are doing, contact us and we will put you on the part MK rates for it.
The second thing that decides blade life here is water. This is a wet blade, and the water is not only there for dust - it cools the core, keeps the segments from glazing and carries the fines out of the kerf. A blade starved of water on a hard mix will cost more than the blade.
Specifications
- Model: MK Diamond MK-525, Supreme Grade for cured concrete
- Manufacturer part number: 134916
- Diameter: 12-inch (305mm)
- Width (kerf): .375-inch
- Arbor: 1-inch
- Segment height: 15mm
- Horsepower range: 12 to 25 hp
- Construction: laser welded
- Cutting method: wet only
- Rated by MK: cured concrete (best), hard aggregate with non-abrasive sand (best), soft aggregate with abrasive sand (best), medium-hard aggregate with abrasive sand (good). Hard aggregate with abrasive sand is not recommended.
- Available in this family: 12-inch through 48-inch
Frequently asked questions
What concrete is the MK-525 rated for?
MK Diamond publishes an application chart for its three cured-concrete grades. On cured concrete generally it rates the MK-500 Good, the MK-505 Better and the MK-525 Best. Broken out by mix, MK rates the MK-525 Best on hard aggregate with non-abrasive sand and Best on soft aggregate with abrasive sand, and Good on medium-hard aggregate with abrasive sand. MK does not recommend any blade in this family, the MK-525 included, for hard aggregate combined with abrasive sand.
What saw does this blade fit?
It runs a 1-inch arbor, the standard flat-saw mount, and MK Diamond publishes a 12 to 25 hp range for the MK-525 family. Confirm the arbor and the maximum blade diameter your saw and blade guard accept before ordering - a 12-inch blade needs a guard rated for it.
Can I run it dry?
No. The MK-525 is a wet-cutting blade and MK Diamond states that its wet cutting blades can never be used dry. Plan on a steady 2 to 4 gallons of water per minute fed evenly to both sides of the blade. The water cools the steel core, holds the dust down and flushes the fines out of the kerf.
How is this different from the other 12-inch MK-525?
By blade width, which MK Diamond prints as a separate part number for each kerf. This part, 134916, is the widest of the three 12-inch MK-525 kerfs MK Diamond publishes (.125, .250 and .375). Diameter, arbor, 15mm segment height, laser-welded construction and the 12 to 25 hp range are the same across the family - the kerf is the variable, and it is what your cut specification and your saw's flanges have to agree with.
Why does my blade stop cutting partway through a job?
Usually glazing. Forcing the cut closes the segments up so fresh diamond cannot expose, and the blade starts riding instead of cutting. Ease off, let the blade cut at its own rate and keep the water on it. If the blade quit with segment still left on it, look at undercutting instead - slurry grinding the steel core away underneath the segments.
Discount Cleaning Products is an authorized MK Diamond dealer. Blades ship direct from stocking inventory, orders are handled by a US-based team that works with contractor and municipal purchasing every day, and we can help confirm diameter, kerf, arbor and horsepower against your saw before you order.
