Refractory brick eats ordinary masonry blades. The MK Diamond MK-440R is built for the hardest end of that material range, and part number 136390 is the 18-inch size. MK Diamond describes this series plainly: for fast cutting and long life on extremely hard Hi-Alumina (70%) brick. The buyers are refractory contractors and industrial maintenance crews relining boilers, furnaces, kilns and incinerators, where high alumina firebrick runs roughly 50 to 90 percent aluminum oxide and is chosen precisely because it resists heat, wear and chemical attack. The same properties that make it a good lining make it brutal on cutting tools.
Built for
- Cutting high-alumina firebrick to size during a boiler or furnace reline
- Kiln rebuilds where arch, wedge and skew brick have to be trimmed on site
- Incinerator and industrial furnace lining maintenance
- Refractory shops pre-cutting brick to a drawing before it ships to the job
- Any silicon carbide or super duty hard brick job where a standard masonry blade glazes over
What sets this blade apart
The economics of refractory work are about downtime, not blade price. A reline happens in a shutdown window, and a blade that quits halfway through a pallet of brick costs far more in lost hours than it ever saved at purchase. That is the argument for a bond formulated for 70 percent alumina rather than a general masonry blade. The laser welded core matters for the same reason: the segments are welded to the steel rather than brazed, which is the more robust joint under the heat and load of a long cutting session. The 10mm segment height MK publishes for this series is the usable diamond depth, and on a material this abrasive that depth is what determines how many brick come off one blade.
Specifications
- MK Diamond part number: 136390
- Blade series: MK-440R, supreme grade
- Diameter: 18-inch (457mm)
- Width: .125-inch
- Arbor: 1-inch
- Segment height: 10mm
- Rim style: segmented rim, laser welded
- Cutting method: wet
- Material: super duty hard brick and high-alumina refractory brick
- MK category: Wet Cutting Refractory Blades (Masonry)
Choosing the right size in this series
MK publishes the MK-440R in three sizes: 14-inch at .110-inch width, and 18-inch and 20-inch at .125-inch width, all with a 1-inch arbor. Choose by the depth of cut your brick requires and the maximum diameter your saw is rated for.
Frequently asked questions
What exactly is super duty hard brick?
It is refractory brick with a high alumina content, generally in the range of 50 to 90 percent aluminum oxide. It is used to line boilers, incinerators, kilns and other high-temperature equipment because it resists heat, mechanical wear and chemical corrosion.
Can I cut refractory brick dry with this blade?
No. This is a wet cutting blade and needs continuous water. Water is also the practical way to control the dust, which is a real concern on refractory work. A dry rated blade can be run wet, but a wet blade run dry can be damaged in seconds.
Why not just use an abrasive chop saw wheel?
Contractors do, for a handful of cuts. The trade-off is that an abrasive wheel consumes itself quickly on alumina brick, changes diameter as it wears so cut depth drifts, and produces heavy dust. A diamond blade costs more up front and is the usual choice once the cut count is high enough to matter.
What arbor and dimensions does part 136390 have?
MK Diamond publishes part 136390 as 18-inch (457mm) diameter, .125-inch width, with a 1-inch arbor and a 10mm segment height.
Will this blade also cut regular brick and block?
It will, but it is not the economical choice. A bond built for extremely hard alumina brick tends to glaze on softer, more abrasive material. MK publishes separate series for standard brick, block and general masonry.
Discount Cleaning Products is an authorized MK Diamond dealer. Every specification on this page is taken from the MK Diamond published product data for part number 136390, not estimated from the part number or copied from a marketplace listing. If you are not certain which diameter, width or arbor your saw takes, our US-based team can check it against the MK series table before you order.
