The MK Diamond MK-190 is a Premium wet diamond core bit, carried here in the 1-1/4 inch cutting diameter as part number 166973. It drills clean holes through porcelain, granite, marble, tile, stone and masonry, and MK designs it to run on any corded or battery operated hand drill rather than a dedicated coring rig. At 1-1/4 inch it is the size most often used for supply lines, larger valve bodies and anchor sleeves.
Specifications
- Manufacturer: MK Diamond Products
- Model: MK-190
- MK part number: 166973
- Cutting diameter: 1-1/4 in (30 mm)
- Cutting: wet only, water cooling required at all times
- Recommended speed at this diameter: 1,000 to 1,500 RPM
- Materials: porcelain, granite, marble, tile, stone and masonry
- Drive: any corded or battery operated hand drill
Note that MK's recommended speed drops as diameter increases: this 1-1/4 inch bit runs slower than the 1 inch, because rim speed at the cutting edge rises with diameter at any given RPM.
Construction
- Vacuum braze technology, with no bond to wear away
- Reverse spiral thread delivers continuous water feed to the cutting surface areas
- Core ejector slot clears debris and plugs
- Hollow bore creates a core that guides the drill
- Heavy-duty, single piece construction
- MK states drilling time is reduced by 50 percent compared with traditional metal-bond core bits
How to run it
MK is explicit that the core bits must be used with water cooling at all times, and lists spray, a wet sponge, a water-feed device, or drilling through a puddle as acceptable methods. MK recommends cordless tools because of the water. MK's technique guidance is to start the bit at 45 degrees so it does not skate across a glazed surface, then bring it level once it has bitten, applying no more than 12 to 15 kg of drilling force.
Range
MK produces the MK-190 in 3/16, 1/4, 9/32, 5/16, 3/8, 1/2, 5/8, 3/4, 1, 1-1/4 and 1-3/8 inch, and states that larger diameters are available.
Mounting
MK does not publish a thread size or shank type for the MK-190 line, so none is stated here. The 5/8 in-11 thread quoted in some search results belongs to MK's MK-290GW granite core bit line, not to the MK-190. Confirm how the bit mounts to your drill before ordering.
Warranty
MK Diamond warrants its bits against manufacturing defects in normal service for one year from the date of purchase by the original consumer purchaser. On brazed bits, MK replaces the bit free of charge if the brazed bond fails within the first .050 in of segment wear. Normal wear, misuse, abuse and unauthorized alteration are excluded, and MK does not pay freight.
Discount Cleaning Products is an authorized MK Diamond dealer based in the United States, with live support if you need help selecting a bit for a specific material.
