Panzer VI Ausf.B (Tiger II) Porsche turret armour.

[Peasant]

Recently I've been studying the Tiger II and it seems unlikely that with such heavy armour it had only 100mm rounded turret front, not much different from Panther (110mm turret face, 100mm mantlet). I'm seeing this number everywhere but I'm beginning to doubt it.
Can anyone confirm or deny this?

[Yoozername]

It is a very odd construction...not the best pic but you can see some welds. perhaps compare to hull 150 mm.

https://blog.tiger-tank.com/headline-news/turrets/

[critical mass]

Recently I've been studying the Tiger II and it seems unlikely that with such heavy armour it had only 100mm rounded turret front, not much different from Panther (110mm turret face, 100mm mantlet). I'm seeing this number everywhere but I'm beginning to doubt it.
Can anyone confirm or deny this?

It´s 100mm min. thickness after shaping in form, this makes the cheeks, where bending is most severe the thinnest areas of the plate. But it was RHA, not cast. Thick cast armor can be made almost as resistent as RHA in perpendicular impact due to similar through section stress tolerances to shear but it will be considerably inferior to RHA obliquely due to the casts armor inferior longitudinal and transverse shear strength (no cross rolling possible).
Increassed resistence can only be gained by face hardening vertical plates -if the attacking shot is of inferior quality or calibre.
There is evidence to suggest that the bended front turret plate (but not the hull front) was differentially hardened (FH) by induction hardening. This could explain why the thickness had to be limited to approx. 100mm.

The british indicated that the 17pdr APCBC and 6pdr APDS could defeat the near vertical 100mm section of the turret front (8" high and roughly 20" wide, of which 12" were covered by the mantlet) at 42° up to a range of 100yd and when facing directly up to 2500. These are calculated, not tested figures, and are based upon the presumption that the cap of the APCBC is effective against FH plate (the use of induction hardening was unknown to the british by then, so they presumed flame hardening here, with only a thin, ca. 4-6mm deep layer of surface hardening (ca. 5% for the 100mm plate), instead of the deep induction hardening).

100mm thick, electric induction hardened plate gave a relative ballistic performance against capped A.P. rated 325 (naval KC/n.A. was rated 330 in this thickness range and homogenious RHA rated 300). The depth of chill of induction hardened armor varied with the rate of advance of the plate between 19% and 30%, with the deeper face beeing intended for what after bending becomes the near vertically exposed section in order to facilitate break up (it was successful against 75mm Pzgr39 in this regard, which could only perforate in unfit to burst condition). This armor could be holed at appox.the same velocity than RHA but complete penetration is only possible at elevated velocity and there will be no explosive filler action possible behind the plate.

[Yoozername]

The Maus turret had similar shape, but greater thickness. I imagine it was cast?

[Yoozername]

A scale model showing the weld lines....The turret is a bad design from the point of manufacture...bending plates like that is not only poor protection, it takes large machinery....

[Mobius]

The Maus turret had similar shape, but greater thickness. I imagine it was cast?

Apparently not. We had a discussion before and it was bent. It lost a few mm in the process.

[Yoozername]

The Tiger I turret manufacturing process.

[Michael Kenny]

[critical mass]

The Maus turret had similar shape, but greater thickness. I imagine it was cast?

Apparently not. We had a discussion before and it was bent. It lost a few mm in the process.

Thats correct. The Maus turret (and likely the tiger prototype turret front plate) was double bend RHA (bend, reheated, bend again, normalized). Its not possible to have a cementated surface in such shapes but a deep chill could be applied in this thermo mechanical process.
You may notice that the slope of the tiger2 front turret is 40deg in the drawing kindly provided by MK, which is the uppermost limit in 42/43 where high quality Pzgr39 can just perforate RHA intact. Against FH, You'd expect them to shatter instead. Any higher obliquity would degrade the ballistic resistence because past 42.5 deg, the projectile tends to initially turn away from the plate, thus RHA will always be better in higher slopes because it doesnt inhibit ricochet by breaking up the projectile.
The series turret worked by absorbing the kinetic energy by plastic deformation, while the prototype turret intended to defeat the shell. I suppose that the prototype turret front would be particularely effective against all uncapped A.P. and high velocity capped A.P. at T/D 0.8 or less, particularely at short range, where striking velocity is highest and the delta between critical break up velocity and actual velocity would guarentee a complete shatter.
these are examples of different resistence concepts.

[Peasant]

Came across some relevant information while reading the Report M6817A: