Jamie Hyneman, who you may know from Discover Channel’s MythBusters, goes through his toolkit and talks about his essential tools. To us, it’s pretty clear that the Knipex High Leverage Diagonal Cutters are his favorite.
The hardness he’s talking about can be quantified as HRC. And he’s right: Knipex has some of the hardest steel around. The high leverage cutters he has have a hardness of 64 HRC, which as he mentioned, is strong enough to cut through piano wire.