The MK Diamond MK-404D 12-inch blade in part number 137307Y is the 7/8-inch arbor version of MK's supreme grade dry cutting masonry blade, built for high speed saws whose spindle takes a 7/8-inch bore rather than the 1-inch standard. It runs a .125-inch kerf and cuts concrete, brick, block and stucco dry.
MK Diamond lists the MK-404D as a supreme grade general purpose blade for concrete and masonry, and flags this part number as one of its high speed blades. The segments are laser welded to the steel core, which is the joint that makes a blade rated for dry cutting and for the rim speeds a gas cut-off saw produces. Supreme grade is MK's top tier in this family, so the buyer here is usually a contractor who has worn out trade-grade discs on the same work and wants a blade that finishes the job rather than the box.
Use Cases
- General purpose cut-off work in cured concrete, brick, block and stucco
- Wall and slab openings, doorways and window bucks where water is not welcome inside a finished building
- Demolition and repair cuts where the saw moves from material to material without a blade change
- Saws and grinder-style cut-off machines built around a 7/8-inch spindle
- Utility and municipal crews cutting in place with a hand-held or walk-behind high speed saw
Why this size and arbor
The Y suffix is MK's arbor code, not a different blade: 137307 is the 1-inch bore and 137307Y is the same 12-inch MK-404D on a 7/8-inch bore. Check the spindle on your saw before ordering, because a bore that does not match cannot be made to fit safely in the field. The .125-inch kerf here is a step heavier than the .110-inch version and gives the blade more body in rough demolition work.
Specifications
- Manufacturer: MK Diamond Products
- Model: MK-404D, supreme grade high speed blade
- MK part number: 137307Y
- Blade diameter: 12 in (305 mm)
- Blade width (kerf): .125 in
- Arbor: 7/8 in
- Segment height: 10 mm
- Rim type: segmented, laser welded
- Cutting method: dry
- Materials: general purpose, concrete and masonry
Frequently asked questions
Is this blade dry cut only, or can it run wet?
It is built and rated for dry cutting. Laser welded segments are what make dry, high speed use safe, and this is the blade to reach for when water is impractical. If your saw has water and the job allows it, running water still lowers heat and dust and will extend the life of any diamond blade.
How do I keep a dry blade from burning up?
Heat is what kills dry blades, and it shows up as a blue discoloration on the steel core just under the segments. Avoid long uninterrupted plunges in hard material. Pull the blade out of the cut every twenty to thirty seconds and let it spin free in the air for a few seconds, which is the cheapest cooling you have on a dry saw.
What does the 10 mm segment height mean?
Segment height is the usable diamond above the core. At 10 mm this blade carries a full segment for its class, so there is real depth of diamond to wear through. When the segments wear down close to the core the blade has reached the end of its life and should be replaced.
What if the blade stops cutting and just polishes the surface?
That is a glazed blade, and it usually means the bond is too hard for the material or the feed pressure is too light. Make a few cuts in an abrasive material such as a soft block or an abrasive dressing stone to expose fresh diamond, then return to the work.
Discount Cleaning Products is an authorized MK Diamond dealer. MK Diamond Products has built cutting, coring and polishing equipment in the United States since 1868 and backs its blades through a US-based service and distributor network, so replacement segments, arbor questions and warranty claims go through people who work on these saws every day. If you are not certain which diameter or arbor matches your saw, send us the make and model and we will confirm the correct part number before you order.
