according Unterlagen zur Bestimmung Hauptkampfentfernung und Geschoßwahl Heft a Textband
Excerpt
As you can see it is explicitly mentioned, that a plate with a different (higher) hardness for the armored deck was choosen, wich provide in accordance with the the revised impact conditions (decapping, distraction, yaw) better performance compared to "normal" plates (with lower strength and greater elongation).The Upper Limit
It should be noted about the safety of horizontal protection against penetration, that results in the pentration-expectations at the relatively small impact angles can only be an indication. Low material differences frequently have a great impact, so for example, differencies in the cap shape(cap removal) and hardness (of the plate Thoddy) can affect pentration abilities in such a way, that in one case, the projectile enters the plate and in the other case, under otherwise the same conditions, ie at the same impact velocity, but with different cap, the projectile will be rejected. Also, the values, both of the angle as well as the impact speeds at which a projectile is dismissed or recently pentrate the plate, often influenced each other so closely, that they can not be separated exactly. Further factor is, that in cases of relatively low impact angles, the elusive nature of distraction has even more impact, than at larger impact angles. This effect can be found especially when several plates have to be pentrated. It is also possible that the projectile enters the plate with an angle to the direction of flight, so it has to pentrate with a much larger cross section.
I hope the translation is ok