You¡¯re right, those bits are great for avoiding the collet change. I have a small battery powered Dremel that is easy to control that I use them in. They are also very sharp! They are easy to break, but so cheap that it barely matters. I used to get mine at train shows too, but those are nearly extinct now. I checked eBay and they appear to be readily available from China:?
I was changing a few mis. items in a drawer just a few minutes ago.? I once bought a box of carbide drill bits from a train-show exhibitor.? I think Micro tool people also sell the same thing--really just a bunch of bits (of random sizes!) in a plastic box, but each bit has a fat collar around it.? I had thought that collar mount would save a lot of time just in not having to adjust the collet size for each bit change.?
I once tried to use them but it quickly broke.? I don't think I've tried any since, so to the back of the drawer they went!? I'm wondering if you gentlemen have used them successfully and how you deal with carbide bits??