German M40 Stahlhelm manufacture and testing circa 1941

German M40 Stahlhelm manufacture and testing at F. W. Quist GmbH in Esslingen circa 1941

The Stahlhelm ('steel helmet') is a German military steel combat helmet intended to provide protection against shrapnel and fragments or shards of grenades. The term Stahlhelm refers both to a generic steel helmet and more specifically to the distinctive German military design.

The armies of major European powers introduced helmets of this type during World War I. The German Army began to replace the traditional boiled leather Pickelhaube ('spiked helmet') with the Stahlhelm in 1916. The Stahlhelm, with its distinctive "coal scuttle" shape, was instantly recognizable and became a common element of propaganda on both sides, just like the Pickelhaube before it.

In 1934 tests began on an improved Stahlhelm, whose design was a development of World War I models. The company "Eisenhüttenwerke Thale" (now "Thaletec") carried out prototype design and testing, with Dr Friedrich Schwerd who was responsible for the original 1915 design once again taking a hand.

The new helmet was pressed from sheets of molybdenum steel in several stages. The size of the flared visor and skirt was reduced, and the large projecting lugs for the obsolete armor shield were eliminated. The ventilator holes were retained but were set in smaller hollow rivets mounted to the helmet's shell. The edges of the shell were rolled over, creating a smooth edge along the helmet. Finally, a completely new leather suspension, or liner, was incorporated that greatly improved the helmet's safety, adjustability, and comfort for each wearer. These improvements made the new M1935 helmet lighter, more compact, and more comfortable to wear than the previous designs.

The Army's Supreme Command within the Third Reich's Wehrmacht or combined armed forces officially accepted the new helmet on June 25, 1935 and it was intended to replace all other helmets in service.

More than 1 million M1935 helmets were manufactured in the first two years after its introduction, and millions more were produced until 1940 when the basic design and production methods were changed to simplify its construction, with the manufacturing process now incorporating more automated stamping methods. The principal change was to stamp the ventilator hole mounts directly onto the shell, rather than utilizing separate fittings. In other respects, the M1940 helmet was identical to the M1935. The Germans still referred to the M1940 as the M1935, while the M1940 designation were given by collectors.

0:05 the process starts with a circular steel sheet that is appropriately lubricated

0:14 the first of a series of presses draws the steel into shape

0:22 the first pressing is lubricated before being passed through the second press

0:32 the third and final press

0:41 the rim is hammered in by hand

0:48 finishing of the rim by rollers

0:53 heat treatment of the formed helmets

1:15 centrifugal drying of the quenched helmets

1:21 painting

1:30 decal application which in this case is the Luftwaffe eagle

1:37 helmet liner added

1:47 the finished product

1:52 proof testing of a sample helmet. While a high velocity round would easily punch through, the helmet could reliably stop low velocity handgun rounds like .45 ACP. The proofing is done with a purpose-made shortened 11mm round firing a lead bullet from a modified Mauser rifle