In 1992 I was working in my father's valve repair shop (waiting to start my MBA progam at Michigan State) when I was helping seat a valve ring in a 4" valve. The air was applied to the valve so the ring wouldn't scar the valve head, and the other guy was holding a pneumatic drill with the key that screws the valve ring in. After years of use, the key was badly flashed (very sharp) around the edges. Anyway, the guy accidentally hit the air hose and knocked it out of the socket, causing the valve to close. The valve head knocked the righ, which threw the key out of the socket and spun it into my right hand. I didn't see it happen, but my vision suddenly went narrow and my head went light. All of a sudden, people in the shop started grabbing my hand and wrapping it. It turns out that the key cut nearly through my right middle and right ring finger. Luckily, three hours of surgery and 128 stitches later, they got everything connected back together.
I returned to work the next day, and on the wall behind where I stood there was a near-perfect out line of my body sprayed in blood, with the clean white spot where I was standing.
My fingers still freeze up in the winter mornings.