Although until 1945, official texts referred only to the "Stahlhelm 1935", collectors and most authors were in the habit of dividing this SH 35 into three models: M35, M40 and M42. There's nothing historical about these designations. According to them, the M35, M40 and M42 can be distinguished by a slight visual modification of the hull, in terms of the vents or the unturned helmet rim for the M42.

In mid-1942, another manufacturing simplification was introduced. The edge of the helmet, hitherto turned inwards, was now left with a clean edge. Slightly curved outwards, it forms a kind of gutter around the helmet. In the meantime, stamping methods have progressed. We've switched to faster, hot stamping, with a reduced number of passes. This is reflected in the inferior finish of M42 shells.
In the collector's world, these hulls are known as M42.

Although until 1945, official texts referred only to the "Stahlhelm 1935", collectors and most authors were in the habit of dividing this SH 35 into three models: M35, M40 and M42. There's nothing historical about these designations. According to them, the M35, M40 and M42 can be distinguished by a slight visual modification of the hull, in terms of the vents or the unturned helmet rim for the M42.

In mid-1942, another manufacturing simplification was introduced. The edge of the helmet, hitherto turned inwards, was now left with a clean edge. Slightly curved outwards, it forms a kind of gutter around the helmet. In the meantime, stamping methods have progressed. We've switched to faster, hot stamping, with a reduced number of passes. This is reflected in the inferior finish of M42 shells.
In the collector's world, these hulls are known as M42.