ILOVETOOL 2.5mm Diamond Drill Bits Tools for Jewelry Making Gem Stone Pack of 20Pcs

Used to drill holes in glass. Worked wonderful using water as a lubricant. Could get very close to the edge of the glass. We were so impressed that we brought in some small stones from the yard, and had fun easily drilling the through them too!

Use water, durable

I’ve been using diamond drill bits for years & these are great! It’s my first time buying but I will definitely be getting more!

Really great glass hole bits!

I'm only giving 3 stars because they almost don't fit tightly in my 1/8" battery Snap-on Die-Grinder's chuck. Other then that they are nicely coated and hold up to many uses.Update: So after my 1st review with only 3 stars the company reached out to me and mailed me the 1/8th bits and they are perfect.

I LOVE these diamond drill bits. I have drilled 4 dozen+ oyster shells with one bit. They are worth every penny. So happy I found them and will definitely order again.

I enjoy lapidary as a hobby and sometimes need to drill a small hole into a stone I have cut. These are just the thing for me to use and have great medium grit (150) diamond plating on the end for about ~1cm. Great value here with 20 in the package; Picture 1. Pictures 2 & 3 show the ends which are ever so slightly dimpled in the center end tip which should improve drilling as the outer rim wears. These do make a fairly large diameter hole a wee bit more than 2.5mm; but for some purposes that is what I require such as a bead.All diamond grit bits MUST be used with water to lubricate the bit. This will carry the grindings away and reduce wear on the tool. I find that using non-hardening Plumber's Putty to build a dam around the stone surface being drilled works well if I cannot direct a steady stream of water onto the stone or drill underwater in a shallow container. NEXT you MUST know that this will "grind" slowly the glass or rock slab and does not "cut" like a toothed burr will in wood or metal. The diamond grit is plated in a thin layer to the outside in this tool; much more costly versions use a thicker sintered diamond layer. Excess pressure will damage and render useless your diamond bit - slow and intermittent light pressure in an up/down manner allows water to enter the hole and carry off debris being ground out. Remember hand and eye protection as glass and stone chips can seriously injure you. I drill especially slowly as I near the break through point to avoid my stone chipping; at times I am able to flip over the piece being drilled and work from the back to meet up with the hole I have started, if I can get the alignment precise.I Highly Recommend these ILOVETOOL 2.5mm Set of 20 Diamond Grit Drill Bits. They are effective and a great value.

Great stone drill bits. Seems to be great quality and consistency between the 20 bits I received. Worked well for cutting stone. Use with water to help keep cool and wash away debris. Good value with this set.