BUT... not for nothing I'm unsure why if I can dent a helm well with a rattan sword that weigh's 3-ish lbs then why is it safe to strike a fencing masked man using a steel sword that weighs 3-ish lbs?
Well, the safety of using a fencing mask is under some debate. But generally, it's considered safe with the appropriate level of control, but not for full-out hard-hitting fights. A lot of folks will use something more substantial for competitions, or when fencing people they're not familiar with.
HEMA/WMA practice with steel generally doesn't use anywhere near the power level that you're used to in SCA. The reasons are two-fold:
1. Such power actually isn't necessary when you're fighting with unarmored techniques. It only takes a modest amount of power for a sharp weapon to deliver an incapacitating blow, particularly in sensitive areas like the face, armpits, etc.
2. Safety, of course. Using a fencing mask with rebated steel simply requires that the participants are controlled and don't strike too hard. But even with a heavier helmet, there are other safety considerations. We're finding that adequate hand-protection is proving to be one of the more challenging aspects, so we have to worry about injuries in other areas too.
