An update and for future reference of future dummies like me: we had an old 1 1/2" brace bit that we cut the tapered end off and ground the end lightly until it fit in my boring machine and it was like night and day with my previous experiences. cut like butter, even though the bit is slightly bent and wobbles. my takeaway is that the flute edges are much thinner than the modern auger bits and thus have less surface contact to bind up. also their are two chiseled cutting edges instead of one. also no spurs, but still a clean hole. also could confirm the previous comments about differences in threads on feed screw. i've been feverishly searching the web for old 1 1/2" brace bits and/or boring machine bits and seems like there are precious few out there.

TIMBEAL, I'd like to buy that Irwin brace bit and do the same thing I did with my antique bit...do you know the diameter of the shank past the tapered end? can't find this info anywhere. if its 1/2" or greater I know I can work it down to fit the machine.

thanks everyone

Boring machine bits should be .500". I've had some that were cut down T-augers, and they were too small, like .440", and you can never get them to chuck in the machine nicely. You should be able to straighten your bent bit. I'd wrap the shank end in something soft, like sheet copper, and clamp it in a vise and gently bend it in the direction it needs to go. I've even grabbed a bit while it was in the boring machine and given them a tweak, but that is risky.

The shank on mine was smaller, so the adaptation. A new shank with a hole in one end and the other 1/2" welded on. I wrapped the cutting end in a very damp wet rag.

I have smacked warped bits with my leather hammer with some success, at least it was better than it was.