Concrete contractors, mechanical trades and anchor-setting crews reach for a small-diameter wet core bit when a
hammer drill will not do the job cleanly. The MK Diamond MK Yellow 1-1/8 in. (29 mm) core bit cuts a smooth,
round, full-depth hole through cured concrete and asphalt without spalling the surface or cracking the slab around
it, which matters when the hole has to accept an adhesive anchor, a dowel or a conduit sleeve that will be
inspected later.
MK lists the Yellow line as its standard grade: a general-purpose bond that is a strong all-around choice for
routine wet drilling rather than a specialty bit tuned to one aggregate. In practice that makes it the bit most
crews keep in the box for everyday small holes, where the priority is a fast, predictable cut and reasonable
footage per bit rather than maximum life in one narrow material.
Built for
- Drilling anchor and dowel holes for handrails, bollards, guardposts and equipment bases.
- Coring small penetrations for conduit, low-voltage sleeves, sensor wells and drain lines.
- Taking test cores and probe holes in asphalt and concrete pavement.
- Setting adhesive and mechanical anchors where a clean, round hole is required for the anchor to develop rated load.
- Retrofit and remodel work where hammer-drilling would risk cracking a finished or thin slab.
How this bit is meant to be run
This is a wet bit. Water does two jobs at once: it cools the diamond segments so the bond wears at the rate it
was designed to, and it flushes cuttings up and out of the kerf so the segments keep contacting fresh material
instead of grinding on their own slurry. Running a wet bit dry is the fastest way to glaze the segments and lose
the bit. The 5/8 in.-11 nut threads onto the arbor found on small handheld and rig-mounted core drills in that
thread class, so confirm your drill's spindle thread before ordering.
Segment height is the usable diamond you are buying. At 7.5 mm, the MK Yellow gives a working depth of diamond
that is re-sharpenable in the normal way, by taking a short cut in an abrasive material such as a block or a
dressing stone when the bit starts to polish and slow down. A bit that has stopped cutting is very often glazed
rather than worn out.
Specifications
- Diameter: 1-1/8 in. (29 mm)
- Nut / thread: 5/8 in.-11
- Segment height: 7.5 mm
- Maximum drilling depth: 14 in.
- Grade: MK Yellow, standard grade
- Segment attachment: laser welded
- Material: concrete and asphalt
- Use: wet drilling only
- Manufacturer part number: 104011
Specifications above are MK Diamond's published figures for the MK Yellow core bit line. Additional diameters
and lengths in this line are available on request.
Frequently asked questions
Is this a wet bit or a dry bit?
It is a wet bit. MK Diamond lists the MK Yellow line for wet drilling, and the bit needs a steady water feed to cool the segments and flush cuttings out of the hole.
What arbor thread does it use?
The 1-1/8 in. MK Yellow uses a 5/8 in.-11 nut, which is the thread MK specifies on its small-diameter bits from 1 in. through 1-1/2 in. Larger MK Yellow diameters switch to 1-1/4 in.-7.
How deep a hole can it drill?
MK publishes a 14 in. drilling depth for the MK Yellow line. Deeper holes call for a barrel extension or a longer bit, which MK offers on request.
Will it cut through rebar?
The MK Yellow is a standard, general-purpose grade. MK positions its premium MK Orange line above it for more demanding work, so for heavily reinforced concrete a premium-grade bit is the more appropriate choice.
The bit has stopped cutting. Is it worn out?
Not necessarily. Diamond bits glaze when the bond does not erode fast enough to expose fresh diamond. Dressing the bit in an abrasive material usually restores the cut if segment height remains.
Discount Cleaning Products is an authorized dealer for the commercial cleaning brands we carry, with US-based product support. If you are matching a part to a machine already in service, send us the model and serial number and we will confirm the correct item before you order.
