Slightly OT as it's for a cycle. I'm trying to undo the pedal (steel) from a crank (aluminium) and it won't shift. Left-hand crank, clockwise unscrew (hopefully).
I've got the crank off and in a vice, used a fair bit of force on the crank, bent one spanner and broken two (all cheap) and it still won't shift. So I'm inspired by this bloke's spanner:
I could get a dedicated pedal spanner, but they look a bit feeble by comparison.
Would it help to heat it? Not sure if the steel might expand more than the aluminium.