This isn't necessarily a tractor issue ,but could be a mower or?
My episode is with a weed eater with a metal blade, my blade seemed to slip, so I tried to tighten it , wrench would not move it , so I clamped visegrips on the blade used my air gun to try and loosen , visegrips came off, spinning blade spun so fast hitting my 4th finger , went right through my fingernail and part way through my finger, so if any-one is removing blades of any kind , don't trust visegrips, make sure the blade is secured solid, keep your fingers clear.

I try to wedge the blade with a piece of wood and will only break the nut loose with a hand tool. Slow and controled.

Stumpy