The MK Diamond MK Yellow 1-1/4-inch (32 mm) core bit (part 156321) is a standard grade, laser-welded wet core bit for general drilling in concrete and asphalt. MK Diamond positions the MK Yellow as an excellent choice for general wet drilling that delivers fast drilling and good footage, which makes it a practical everyday bit for crews who core many holes and want dependable cost per hole.
This 1-1/4-inch size is a good match for small-bore holes for anchors, conduit and sensor or pipe penetrations. It has a 5/8-11 nut for your core drill and a 7.5 mm segment height with a 14-inch drilling depth.
Use cases
- General concrete coring. Drill round holes through slabs, walls and footings with a wet coring rig.
- Asphalt coring. Take clean samples or open penetrations in asphalt pavement.
- Plumbing and electrical rough-in. Open penetrations for pipe, drain and conduit runs.
- Anchor and utility work. Cut accurate holes for sleeves, fixtures and service lines.
Specifications
- Brand: MK Diamond
- Series: MK Yellow standard grade segmented core bit
- Part number: 156321
- Diameter: 1-1/4 inches (32 mm)
- Segment height: 7.5 mm
- Drilling depth: 14 inches
- Nut / thread: 5/8-11
- Construction: Laser welded
- Use: Wet drilling only
- Materials: Concrete and asphalt
Fit and compatibility
Core bits are chosen by diameter and thread, not by drill model. Confirm that your core drill or rig accepts a 5/8-11 thread and that the 1-1/4-inch size and 14-inch depth suit the hole you need. MK Diamond notes that other diameters and lengths are available on request, so contact us if you need something different.
Getting the most from the bit
Run the bit wet with a steady, adequate water supply, keep the drill aligned and let the segments cut at a smooth, even feed rather than forcing the bit. Pulling the bit out periodically on deep holes helps clear slurry. If the bit starts to cut slowly after hitting steel or a very hard aggregate, stop and inspect the segments, and wear eye, hearing and slurry protection for the job.
Frequently asked questions
What is the MK Yellow 1-1/4-inch core bit used for?
MK Diamond describes the MK Yellow as a standard grade core bit for general wet drilling in concrete and asphalt.
Can I use it dry?
No. MK Diamond lists the MK Yellow as a wet drilling bit, so use it with a water supply.
What thread does part 156321 have?
It has a 5/8-11 nut.
How deep can it drill?
The listed drilling depth is 14 inches, and MK Diamond says other lengths are available on request.
Should I choose MK Yellow or a higher grade?
MK Yellow is the standard grade for general wet drilling. MK Diamond lists MK Orange as a premium grade for light to moderate steel reinforcement and MK Black as a supreme grade for moderate to high steel reinforcement.
Discount Cleaning Products is an authorized MK Diamond dealer, and our US-based team can help you match the right bit diameter, thread and drill rig before you order.
