beware of big bits of metal.
a bit ago I was attempting to get a transit propshaft apart, the kind with a middle joint. one end held in the vice, the other end propped on a handy surface. The middle flange has a bolt in the centre, holding it onto one half of the shaft, and this has to be removed to get the flange off and remove the centre support bearing, which is buggered, and it's a right bloody fiddle getting the bolt out, as its head is in the middle of a UJ.
At exactly the wrong moment the propped end slipped and came >< that close to cutting the end of my left index finger, or it felt like it at the time.
Actually, it's nastily crushed but not broken and should recover OK, but it's sodding painful.
take it easy out there and be aware that heavy things can hurt.