The later Centurions were pretty good for an all steel tank though. Though from the picture above, even without Stillbrew, it's pretty thick along the direct front of the turret; the sides not so much.
I wouldn't be surprised if it was close to 200mm at whatever inclination the slope is (which would put it in the high 200s).
Which isn't enough against the 115mm APFSDS as we all know (BM-4 is around 270mm IIRC), but it's still pretty good for a "big tank".
Turret 195mm @ 60d = 390mm
Hull 120mm @ 72d = 388mm
DKTanker, if it is for Chieftain (as I guess), this data are obsolote. Glacis is circa 85 mm, turret front is circa 140-150 mm. A little more than equivalent for 120 mm at 60 degrees like FV 4201 was designed for.
Edited by Przezdzieblo, 27 July 2014 - 0507 AM.