Ratings & Reviews for Kobalt Diamond Core Drill Bit 5/16-in Dry Diamond Core Drill Bit for Stone

Performed as expected

I needed a small hole saw to bore through newly installed tile for a toilet paper holder. I first marked the location of the two holes. I wanted to use it wet, so I had my wife hold a wet sponge above each location and slowly squeeze as I drilled. I quickly learned that it's near impossible to hold a hand held drill on the target spot with the end of the bit flat against the tile. You have to start it at an angle to get your first bite, then gradually straighten the bit as it cuts. It performed ...

Good Hole Drill

Found it works well. Got this to work with roofing slate. The only issue is starting it with a hand drill is that it tends to walk. But once you master that it works very well

Good Hole Drill

Found it works well. Got this to work with roofing slate. The only issue is starting it with a hand drill is that it tends to walk. But once you master that it works very well

Very Good Bit

Starts fairly easily at higher speed at an angle. Makes a clean hole with very little chipping. Very fast to complete the cut. No noticeable wear on the bit after drilling. Wet drilling is faster than dry. Overall, a very good drill bit for ceramics.

Very Good Bit

Starts fairly easily at higher speed at an angle. Makes a clean hole with very little chipping. Very fast to complete the cut. No noticeable wear on the bit after drilling. Wet drilling is faster than dry. Overall, a very good drill bit for ceramics.

Very Good Bit

Starts fairly easily at higher speed at an angle. Makes a clean hole with very little chipping. Very fast to complete the cut. No noticeable wear on the bit after drilling. Wet drilling is faster than dry. Overall, a very good drill bit for ceramics.

Very Good Bit

Starts fairly easily at higher speed at an angle. Makes a clean hole with very little chipping. Very fast to complete the cut. No noticeable wear on the bit after drilling. Wet drilling is faster than dry. Overall, a very good drill bit for ceramics.

Not the best option

Difficult to start cleanly, bit skates over the surface. Center hole fills with material and slows drilling down. Not very fast even at speeds higher than recommended. For this size hole, this bit is harder to use than a single point bit. Hole was clean with little chipping.

Difficult bit

Tried the quick change ¼” shank but preferred to insert directly into drill chuck. Bit seemed to work much better wet than dry. Slotted for material extraction, but center of bit fills up, particularly if wet. For a ¼” hole, this bit was very hard to start and skated easily on tile. Packaging says to operate at maximum speed of 400 rpm, but needs to operate much faster to drill in a reasonable time. Appears to be durable with no signs of wear after one hole. Not the best option for this small ...

Fast clean cuts

Does cobalt wholesale makes fast clean cuts. The one and three eights inch size makes it perfect for cutting through tile, ceramic and so forth for installing inch and a quarter waterlines for drains for vanities . It made a fast clean cut With no cracking or chipping of the ceramic tile. I particularly like the large clean outs on the sides that you can simply stick a screwdriver in and knock out the plug that you just cut. I have always had great success with Kobalt tools And this is no di...

Great

This works great for cutting holes in boards and timber! Wish it had a pilot cutter as well though! It’s Kobalt so it will last a lifetime! Fits any drill and super sharp! Definitely recommend this tool for your toolbox!

Superb Quality

This saw bit is a great quality product you expect. Although I did not have a piece of granite, marble, ect to use it on, it will work like a dream when that time comes around! Very sturdy construction and well made. When I get new countertops put in the kitchen, this should be the perfect size for making holes for kitchen faucets. It can be used on dry or wet applications.

Great hole saw for tile

I wasn’t sure what to expect with this. I’m used to having an arbor to make sure my hole is where I want it. I soon figured out the trick is to start an edge then straight down. It cut extremely well. Did not chip the edges.

Cuts well

This one was a little bit of a challenge. Being only 1/4”, it’s not as easy to start it. It wants to travel on you. If you’re able to hold it still enough for the edge to start, you will be fine. Like the others, the edges were clear of chipping, and smooth.

Clean cutter

I wasn’t sure what to expect with this. I’m used to having an arbor to make sure my hole is where I want it. I soon figured out the trick is to start an edge then straight down. It cut extremely well. Did not chip the edges.

Easy to use

I wasn’t sure what to expect with this. I’m used to having an arbor to make sure my hole is where I want it. I soon figured out the trick is to start an edge then straight down. It cut extremely well. Did not chip the edges.

Cuts like butter.

I wasn’t sure what to expect with this. I’m used to having an arbor to make sure my hole is where I want it. I soon figured out the trick is to start an edge then straight down. It cut extremely well. Did not chip the edges.

cheaply made

Twisted like a bread tie with even a mild ankint of force applied.

Perfect

Only needed to make a few cuts. Worked fine. No problems