Stopped in to a local second hand metal supplier. They have lots of reclaimed metal. They also have tools, motors etc. They had a bin of new Chicago Latrobe 57/64th drill bits. I don't have many larger bits and for 2 bucks couldn't pass it up. Problem is I don't have a chuck to hold it. Would you make an adapter to hold the bit that would fit my chucks, or try and turn the bit shank to a smaller size?
I have a few around I've WELDED to get longer shanks than I had to-hand, but it isn't easy to get 'em centered.
"Jacobs type" chucks (or Albrecht type) - largest here is 3/4" - simply don't HOLD well above 3/4" even if you had such an animal.
You didn't tell us what spindle you expect to use it on, nor what, if any, other options you have for said spindle or spindles, plural, besides a "chuck"?
My case, ER, Rubberflex, or TG, for lathes, mills, and the larger drillpress. So it's fine as it is.
PITA to turn a HSS shank, (prolly M42?) down, if only 'coz they are a nuisance to center and still get a decent grip on.
But you might have to drop clear to 5/8" for the more common Jacobs chuck. The 3/4" inch capacity ones are bulky and not that common. And NOW you will also need three flats - as Silver & Deming's use - lest you just slip it instead of driving it. Most of my larger drills have MT shanks, anyway, so..