The armour on the Cromwell ranged from 8 mm up to 76 mm thick overall. On all-welded vehicles built by BRC&W, the weight saved by the welding allowed for the fitting of additional appliqué armour plates on the nose, vertical driver's plate and turret front, increasing the maximum thickness there to . These vehicles are identified by their War Department numbers carrying the suffix W, e.g. T121710W. The armour compared well with that of the Sherman, although the Cromwell did not share the Sherman's sloped glacis plate.