The MK Diamond MK-505 (part number 135087) is a 12-inch wet-cutting segmented diamond blade for cured concrete, built for the crew that has to open a slab and get the saw back on the truck the same day. It is the blade a concrete cutting contractor, a DOT or municipal maintenance crew, or a demolition sub reaches for when the cut has to be straight, full depth, and finished without stopping to swap blades halfway down the line. Because MK Diamond matches the premium-grade bond specifically to cured concrete, you get a predictable cost per linear foot instead of the three-blades-for-one-job outcome that comes from buying on sticker price alone.
Use cases
- Full-depth cutting of cured concrete slabs ahead of breakout and removal
- Cutting control joints and expansion joints in slabs that have already set
- Utility and conduit trenching through existing slabs, drives and aprons
- Squaring concrete patch and dowel-bar repairs so the pour has a clean vertical edge
- Curb, gutter, sidewalk and pavement layout cuts on walk-behind flat saws
Built for your saw
MK Diamond rates this blade for saws in the 8 - 20 hp range and cuts it to a .375-inch kerf. Those two numbers belong together: a wider kerf removes more material per pass and demands more torque, while the extra core thickness resists lateral flex and keeps a long cut tracking straight under a heavy machine. Running a wide-kerf blade on an underpowered saw bogs the cut and glazes the segments; running a blade that is too thin on a big machine gives up stability. This one is sized for a walk-behind flat saw with a 1-inch arbor.
What the Premium grade gets you
The MK-505 is the premium-grade tier of MK Diamond cured-concrete wet blades, spanning 12-inch through 36-inch diameters. Within that family, MK Diamond publishes this blade as rated Better on cured concrete and Better on medium-hard aggregate with non-abrasive sand. The segments are laser welded to the steel core - the joining method the manufacturer specifies for wet blades in this line - and stand 12mm tall when new, which is the wear material you are actually buying. The practical benefit is not a faster first cut; it is that the bond keeps exposing fresh diamond at the rate the concrete in front of it wears it away, so the blade stays sharp deep into its life instead of glazing over partway through the job.
Running it well
Feed water continuously to both sides of the blade and never let it run dry - contractors consistently report that a wet blade run dry loses segments or warps its core, and water is also the dust control OSHA Table 1 names for walk-behind saws. Let the blade reach full speed before entering the cut, step down in passes rather than dropping to full depth in one plunge, and keep the saw tracking straight so you are not side-loading the core. If the blade starts to glaze, a few feet in abrasive block or a dressing stone will re-expose the diamond. Handled that way, a segmented blade in concrete commonly returns somewhere in the 3,000 to 5,000 linear foot range, with aggregate hardness moving that figure the most.
Specifications
- Manufacturer: MK Diamond Products
- Model: MK-505
- Part number: 135087
- Grade: Premium
- Material: Cured concrete
- Cutting method: Wet
- Diameter: 12 inch (305mm)
- Width (kerf): .375 inch
- Arbor: 1 inch
- Segment height: 12mm
- Horsepower range: 8 - 20 hp
- Core: Laser welded
Frequently asked questions
Does the MK-505 135087 have to be run wet?
Yes. This is a wet-cutting blade and it needs continuous water at the cut. Water is not optional cooling on a blade like this - running it dry risks segment loss and core warpage, and published contractor guidance puts the blade-life difference between wet and dry operation in the range of five to ten times. Water also suppresses respirable silica dust, which is why OSHA Table 1 names an integrated water delivery system as the control for walk-behind saws.
How deep will a 12-inch blade cut?
A circular blade can only reach about half its diameter, and the arbor, flanges and blade guard take roughly another inch. The working rule contractors use is radius minus about one inch, which puts a 12-inch blade near 5 inches of usable depth. Confirm against your own saw, because guard and flange dimensions vary between machines.
Which grade should I run - the MK-505 or another tier in this family?
MK Diamond publishes an application chart for this family. The MK-505 is rated Better on cured concrete and Better on medium-hard aggregate with non-abrasive sand. The MK-505 is the premium-grade tier of MK Diamond cured-concrete wet blades, spanning 12-inch through 36-inch diameters. Pick the tier by the aggregate you are actually cutting, not by price alone.
Why does bond hardness matter when the segments are diamond?
The diamond does the cutting, but the metal bond holding it decides how fast fresh diamond is exposed. The rule runs backwards from what most people expect: hard, non-abrasive material calls for a softer bond so the matrix erodes and keeps exposing diamond, while soft or abrasive material calls for a harder bond so the segments are not worn away prematurely. A mismatch shows up as glazing, a blade that stops cutting, or segment life that ends far too early.
What kind of blade life should I expect?
Published industry figures for segmented diamond blades in concrete commonly fall between roughly 3,000 and 5,000 linear feet, but that spread moves a long way with aggregate hardness, water supply, saw horsepower and feed rate. Abrasive mixes can cut it well below that range and softer material can push past it. Matching grade and kerf to the job is what keeps cost per linear foot predictable.
What arbor does it take?
A 1-inch arbor. It mounts on any flat saw with a 1-inch shaft in the 8 - 20 hp range without a bushing or adapter.
Discount Cleaning Products is an authorized MK Diamond dealer. MK Diamond Products has manufactured cutting, coring and polishing equipment in the United States since 1868, and its blades are backed by US-based technical support and a nationwide service center network. If you are unsure whether the Premium grade or a different tier in this family matches the aggregate on your job, contact us before you order and we will work it through with you.
