"You know that's hardened steel," said the guy at the auto parts shop. "You're not just going to be able to cut it."
Why am I doing this? Because Honda VT1100 engines use 18mm spark plugs, but the spark plug wells are much narrower than a normal 18mm spark plug well. You need an '18mm narrow extractor' which, coincidentally, only Honda seems to make. That, my friends, is why Crom gave us carbide steel: to cut all other steels.
Too bad I didn't get a pic when it was smoking...