regarding rings: I went on a fairly serious first aid course years ago and there were a lot of very grim picture of "ring injuries". I'd never worn jewellery of any sort, and neither my father nor grandfathers had worn wedding rings, so eschewed a ring when I married, in part as a result of said pictures, but also a "wedding rings for blokes ? I'm not an American you know" sort of thing. Having married a second time, neither of us were fussed on rings, just as a "stuff and nonsense" kind of attitude. I still recall the picture. Whilst I don't work in engineering and am a shiny arsed IT consultant, I still do the odd job in the house and go caving and such, so no rings for me.
And back to the OP, whilst a freak accident, kinell, that is horrific and I hope the lad recovers.