Repointing starts with getting the old mortar out without touching the brick. The MK Diamond MK-404DT is a supreme grade tuck point blade built for that job: a thick .250 inch double rim that cuts a mortar joint to width in a single pass, laser welded to the core so it holds up to the side load an angle grinder puts on it. This 4-inch size is the one masons run for tight, overhead and in-corner work where a larger blade cannot reach.
Built for these use cases
- Removing deteriorated mortar from brick and block joints ahead of repointing
- Grout repair and joint cleaning on masonry walls, chimneys and parapets
- Cutting control joints and cleaning out old caulk joints in concrete
- Scoring faux joint lines in decorative concrete and stamped overlays
Why the .250 inch double rim matters
A standard mortar joint is roughly 3/8 inch. A thin cutoff wheel leaves you making two or three passes and walking the wheel down the joint, which is how brick faces get nicked. The .250 inch width of the MK-404DT takes out the bulk of the joint in one pass and leaves a straight, square channel for the new mortar to key into. The squared segment profile is bonded for the Portland cement, sand and hydrated lime that make up typical mortar.
Laser welding is the other half of it. Tuck pointing is almost entirely side-loaded cutting on a vertical or overhead wall, and a laser welded joint between segment and core is what keeps a segment from letting go under that load. Run it dry, keep the grinder guard on, wear eye and respiratory protection, and pair it with a dust shroud and vacuum where silica rules apply.
Specifications
- Model: MK Diamond MK-404DT, supreme grade tuck point blade
- Diameter: 4 inches (102mm)
- Width: .250 inch
- Arbor: 7/8 inch to 5/8 inch
- Segment height: 10mm
- Construction: laser welded
- Use: dry cutting
- Tools: angle grinders, circular saws and tuck pointers
- MK Diamond part number: 139790
Frequently asked questions
What does .250 inch width mean for my joints?
It cuts a channel a quarter inch wide. On a typical 3/8 inch mortar joint that removes most of the joint in one pass, so you are not walking a thin wheel back and forth and risking the brick face.
Is the MK-404DT a wet or dry blade?
Dry. MK Diamond builds the MK-404DT for dry cutting with angle grinders, circular saws and tuck pointers. Pair it with a dust shroud and vacuum to control masonry dust.
Will it fit my angle grinder?
It has a 7/8 inch arbor that steps down to 5/8 inch, which covers the great majority of angle grinders and tuck pointers. Confirm your grinder is rated for a 4-inch blade before mounting it.
Can I use it on concrete as well as mortar?
Yes. MK Diamond rates the MK-404DT for mortar removal, grout repair and cleaning of concrete applications. It is not a general purpose cutoff blade for deep concrete cutting.
How does supreme grade differ from standard grade?
Supreme grade carries higher diamond content and a bond built for a harder duty cycle, so it holds its cutting rate longer in abrasive mortar than a lower grade blade.
Discount Cleaning Products is an authorized dealer for MK Diamond, with US-based product support to help you match the right blade to your equipment and your material.
