Why steel helmets for HEMA steel sword sparing? Because...

[Sir James A]

If someone is fighting BOTN or SCA style in a WMA/HEMA battle by trying to use brute force instead of refined technique, and subsequently bashing fencing masks in ... that person needs to be removed immediately as they are an unsafe competitor.

That has nothing to do with the safety of the mask; it's the training (safety) of the people wielding the weapons.

[Sir Brian]

That has nothing to do with the safety of the mask; it's the training (safety) of the people wielding the weapons.

QFT! Sir Edward and I (mostly me though) had a bit of an issue with our power levels in training yesterday since we've both haven't down any real training in a month our control was a little off and we were landing some pretty hard hits on each other. - Again my apologizes Sir Edward! 

[Sir Edward]

Oh it's OK. We were both ramping up a little. Those hits were just getting a little into the heavy side, so I thought I'd mention them before we ramped up further. I was doing it too though. So it's all good.

[Sir William]

That's why you can safely hit a fencing mask with a steel federschwert, but you need a 12 gauge steel helm for rattan.  Physics

That's also a really good answer.

Oh I see! So I wouldn't have gnarled fingers if I didn't take that 'physics' to the hand? 

Yes, for that is 'applied' physics.  lol

[Sir Nate]

you know I used to be an adventurer like you, until I took a sledge hammer to the bucket.