Like the gentleman said, the tiny ones will break. That is why I buy the sizes I use the most, by the dozen. I also buy mine from Mike's Workshop. They are the only ones I have used, so I do not know if there are better ones of that small of size. If you are buying Irwin, from ACE, I don't think they carry the small sizes, like #63, #65, #68, etc. Least my ACE doesn't. The probably only go down to 1/16". I have not had any real problems with Irwin that I have used. I break some, but it is usually my fault.
Now, I bought a little set of bits at Sears once years ago, off of a bargain table. They were an off brand. The first one I used was to drill a hole in some pine. It was a 3/16" bit. I just folded over when I started to drill, like maybe it was made of soft lead. Got a laugh out of it as I threw the whole set in the garbage.