12mm

These arrived and though I haven’t used it yet, I have been observing how sturdy their construction seems. These are great for dowels in furniture. Highly recommend these.

No issue

A carbide cutting edge is the hot ticket when cutting manufactured-wood materials like MDF, masonite, particleboard and even plywood. These are a durable alternative for making holes in those materials.These have a brazed carbide tip with a clean four-facet grind leaving a brad-point in the center. The cutting lips are slightly hollow-ground producing a bit of a spur at the edge to sever fibers and reduce tearout. The cutting-lip edges are chamfered to also contribute to a clean-edged hole.I like these and they save subjecting my brad-point bits to abrasive materials. There is a flat on the shank which I expect registers them in the doweling tool they're intended for, but you can chuck them up in a regular drill chuck as long as you avoid that flat with any of the three chuck jaws, which is how I use them.Overall, I'd do it again and recommend. The price of $15 each (two for $30) seems a good value to me.

I have a set of smaller dowel jointing drill bits but needed some with a larger diameter for a project I have been working on, and these are perfect. They fit perfectly and securely into to my dual spindle dowel jig and performed very well.They come in protective sleeves, which is extremely nice to keep them protected, but more importantly, keep me and my son protected. He is just learning to properly handle sharp tools. The shafts are also secured in a hard plastic holder. This makes them easy to handle and move around safely, but they are difficult to pull out to use. I had to tightly grab the spiral part of the bit, which is not sharpened, and use some force to pull them out of the socket they are in. I really didn't like the amount of force I had to use. A person without a lot of hand and finger strength might have some difficulty doing this.The actual cutters are very sharp and do an excellent job. However, just like any other sharp tool, these could easily cut the skin if handled inappropriately.If looking for drill bits for dual dowel drilling, you can't go wrong with this set.

I wish I could afford a Festool domino jointer, but I can't. I can afford the Igoo doweling jointer, and It is awesome. I like that I can change out bits for larger / stronger dowels depending on the project. These bits are excellent quality, they fit perfect in the machine and cut a super clean hole with ZERO tear out. These are a great accessory to have with your doweling jointer.

I used these bits yesterday with my dual spindle jointer. Nice, sharp bits, accurate size, and they worked great.I don't know what else you need to know. These worked great for me, and I imagine they will continue to do so for a while.

This drill bit cleans the holes clean for my dowel, I got various sizes so I can change them out depending on my woods thickness. Leaves the holes clean, so very accurate cutting ability.

Perhaps I'm not very smart, but reading the description, I thought these would be sufficient to make doweling joints. I got these without realizing that I needed a $125 power tool with which to use them. As far as I can tell, they're useless to me. Do they work well? Maybe? We should all strive for better written communication.