[William P]

i know the answer is 'it depends but some basic figures would be good

specifically ive seen tests of some made by iron mountain armoury and i was stunned at how easily and deeply thewy were deformed by sword strikes.. in the chest, tassets, arm pieces etc
https://www.youtube.com/watch?v=D9OvaL2W6BA as shown here

how realistic is this armour? both in the latse sengoku period/ korean campaign, all the way up to the edo period?

[Dan Howard]

Armour is meant to be damaged. The more energy that is expended stretching, twisting, and denting the armour means that less energy is transferred through to the wearer. Today we overbuild our armours because we can't afford to get them mended after every event, but a lot of historical armour is lighter and thinner than we would have thought practical. If you survive a battle with your armour so damaged that it can't be used any more then it is doing its job. If you came out of a battle with your armour undamaged then you'd be accused of not pulling your weight, if not of outright cowardice.

[Timo Nieminen]

I think the Iron Mountain armour is thinner than historical, for late Sengoku Jidai. Bullet-resistant breastplates and helmets would be 3-4mm thick. That's pretty dent-proof if you hit it with a sword.

Iron/steel lamellae might be about 1mm, or even a little less, and rawhide lamellae about 6mm. Thin lamellae like that will deform easily enough. Note that lamellar armour would usually have 4 thicknesses overlapping.

Some Edo Period armour was thinner, much thinner. Too thin to keep out arrows, let alone bullets. Made for show, not fighting.