Saksalaisen teräksen koostumus muuttui vähän aivan sodan loppuvaiheessa, mutta yleisellä tasolla saksalaisten RHA teräs 255-335 BHN oli yhä parasta; laatu oli parempaa kuin liittoutuneiden. Mutta esim. Tiger II:n teräskoostumus ei ollut yhtä hyvää kuin Tiger I:n; teräksen koostumukset ja niiden erot käyvät ilmi mm. Jentz:n ja Spielberger:n Tiger-teoksista.
Robert Livingston: kirjoitti:
"…US WWII armor was of the softer type, about 250 BHN, while most other nations used harder steel…the British found the T34 armour to be of a reasonably high quality with an armour hardness measurement of about 350-400 BHN…Russian tank armor was at 400-450 BHN during the later stages of the war…only the Germans utilized decent-quality rolled alloy plate for tanks…the Germans used face-hardened armor at first, with file-resisting hardness, then dropped the face hardening and relied on the core hardness of 250-300 BHN, similar to US tank armor…generally, hard armor is expected to break up attacking projectiles, which it can do when it is thicker than the diameter of the projectile…soft armor is best at absorbing projectile impact through slower deceleration… penetrating caps (APBC, APCBC, APCR) were so effective that the FH armor (FHA) resisted less well than softer homogeneous armor (RHA)…Face Hardened armor is best at defeating uncapped AP when it overmatches the projectile, that is, the diameter of the round is less than the thickness of the armor…Caps on APC and APCBC defeat FH by encouraging crack formation in the hard brittle surface…Rolled armor is ballistically superior to cast armor due to the compaction and consolidation of grain structure which occurs during rolling… during WWII there was constant tension in Germany between those who thought Tungsten carbide should be reserved for the machining of steel and those who thought it should be used on the battlefield for the penetration of armor…Curved surfaces distribute stress better than sharp-cornered welded boxes, so curved mantlets acted a bit thicker than their weak granular structure would lead us to expect…Nothing much below 210 BHN was used with good results…German 85-200mm specs at the end of the war called for 220-266 BHN. 55-80 was 250-290 BHN, and 35-50mm was 300-350 BHN. Much armor in that range was face hardened, with a 450-600 BHN face…By the end of the war the US had tested German projectiles and found them significantly better than ours, against our own and British plates. As their penetration data for their own guns showed, the Germans were able to make VERY resistant plate through the end of the war for their own test programs…on average, hardness of cast was less than rolled…rolled armor is essentially cast armor which has been further worked and shaped…Homogeneous armor works best when it is the same hardness throughout, as changes in hardness form stress concentration boundaries which destroy ballistic resistance…Certain alloys such as chromium deepen the internal hardening, but Cr supplies in Germany quickly became limited. Due to the difficulties in making thick plate, optimum BHN drops as the thickness increases, as softer plates are more forgiving of heat treating errors…The quality of AFV production armor suffered, though. The loss of nickel and molybdenum supplies was critical, and they could only compensate successfully on a proportion of the plate delivered, due to the finicky and troublesome interrupted-quench system, wherein plates were hoisted in and out and back into huge quench pools, with timing to the nearest second…I believe the Panther glacis often was defeated at the mill, with a 10-20% reduction in effective thickness due to incorrect quenching and tempering…A metallurgical report on a Panther glacis showed the presence of bainite, a crystalline form of steel, in an interior layer (like plywood…
US cast armor was of the following BHN:
<32mm: 302-325 BHN
The following BHNs apply to US rolled armor:
25mm: 310-350 BHN