Being a Machinist, I know that I would not chuck a 1/4 inch piece of steel unsupported more than. 1 to 2 inches from chuck. Now to current situation. Facility I work at has a lab, in this lab they have 2 ancient drill press that use a standard Jacobs chuck (never seen replacement nor inspection that I know of) the tech there use a 10 inch long 1/4 inch rod with a 3 blade agitator to mix samples. Recently a tech was using one and was adjusting rpm from 4000 down to 1000 as required by procedure. Having to use a hand held tach (kind of archaic). Shaft took to wobble, resulting in a 90 degree bend at chuck. Caught his hand and did major damage. Management is now in the investigation step and being a former machinist I had spoken up about the dangers of running something that long, that small, unsupported. Let alone in a 3jaw Jacobs chuck. Some of the engineers are adamant that it couldn’t have bent without him hitting it. That’s not my opinion. I’ve seen way to many things thrown out of machines or alignment do to centrifugal forces. I have searched and cannot find any materials to help my plant manager solve this issue or come up with a root cause. Sorry for the long post, but I thank anyone that took the time to read and would offer some insight. This tech is still in hospital and and any solutions I can offer may help save any future accidents from occurring. Thank you