Looking for an adaptor

I'd question whether it is worth it. Those bits are designed for cutting at very low speed and high load. Thanks to China a set of reasonable Augers or Forstner bits is very affordable.

I think you might be out of luck there with the extensive use of hand tightening chucks on modern drills and the conversion of many of the bits formally used with a brace to fit three jaw chucks I cannot see anyone bothering to make a replacement chuck to fit drill bits that are now getting harder to find. I must admit I find augers used in power drills very easy to overdrill the depth owing to the screw guide feeding the drill in rather than the pressure applied by the user. If you have a number of brace bits that you want to use then cutting off the taper end off them might be your only solution.

Richard

That's what I did before. Would be nicer to keep these as is. Maybe I could contemplate moulding something in plastic, probably be strong enough for small bits.

NT

It's easy to find adapters the other way round, but not to enable an old bit to be used in a modern hex drill.

NT

My old b/D drill seems to be able to clamp any old shape in its chuck, whether by accident or design. Brian

I was going to suggest a deep spline socket might do the job, until I remembered what shape the shaft was at the other end!

cut one of these up

If you have one of those it would be better to just use it as intended - those drills often aren't really usable at power drill speeds, even the lowest.

Would it be possible to turn down the end part of the taper so a conventional chuck would grip while retaining enough taper for the hand brace? Probably not.

Cheers

they don't work. Ones that do, I'd not reasonably expect that type of chuck to be able to do the job.

NT

I've had no problem using cut off ones in cordless drills.

NT

Yes, cheap forstner bits from TNPs favourite shop would be much better or even a spade drill in a powered drill.

The spiral is too coarse for a fast speed.

snipped-for-privacy@gmail.com used his keyboard to write :

If you must, just saw the square part off.

It's exactly the same as modern augers. It's not a problem.

NT