An estimated 25 million German helmets were produced between 1935 and May 1945. These were manufactured by a number of firms, including some which had gained experience through the production of helmets during World War I. In the early years the firm of Eisenhuttenwerke at Thale and the Sachsische Emaillier and Stanzerwerke at Lauter would lead the production efforts; other firms experienced in steel manufacturing and shaping would be added (see Table 1). In 1936 a helmet cost 6.00 Reichmarks; this price later fell to RM 2.80 as a result of design improvements and larger production volume. Helmet shells were manufactured in six different centimetre sizes (60,62,64,66,68,70), of which each could accept one of only two differently sized liners. Approximately 80 per cent of all helmets were produced in the 64cm and 66cm shell sizes, with the oversized 70cm version being manufactured in very small numbers. Each helmet was marked on the inside left rim with its shell size and abbreviated factory designation. On the inside rear rim appeared a numeric or alpha-numeric factory production code designating the lot in which the helmet had been produced. The Thale plant and the firm of Quist at Esslingen would later change their factory designations and placed their maker stamping in the rear of the helmet above the production code; these were denoted by 'ckl' and 'hkp' respectively. Prior to the development of the M1935 helmet, German industrialists experimented with a unique composite material known as 'Vulkanfiber'. This lightweight material became the first substance used in early prototypes leading to the development of the M1935 helmet. The Model 1933 Vulkanfiber helmet On 18 March 1932 the Army High Command ordered the testing of a new prototype helmet that was intended to replace the older World War I models. This new helmet was entirely composed of a heavy plastic-type material known as Vulkanfiber. The Model 1933 Vulkanfiber helmet retained the basic shape of the standard helmet but was much lighter. The helmet was designed in two different styles, of which the first had a longer frontal brim, while the second had slide slots for hanging the chinstrap when not in use. The left side of the helmet allowed for the attachment of a metal shield bearing the Reichswehr provincial insignia of the wearer. Both models were placed into limited production following favourable field tests which concluded on 15 March 1933. Further testing was ordered on 4 May 1933, and small numbers were issued to a variety of Reichswehr infantry, artillery and communications troops. The helmet was removed from service and testing stopped following the successful introduction of the M1935 steel combat helmet. With the advent of the M1935, many of the remaining M1933 helmets were removed from military service and reissued to civilian organizations including fire brigades and city, rural, and railway police units. Clearly visible in this portrait of an Eastern Front veteran is the M1942 Helmet with flared rim. A dark patch on the left side shows where the Army service emblem was located before being scraped off In accordance with the directive of 28 August 1943. The Model 1935 steel helmet In 1934 testing began of an improved steel combat helmet whose design showed a development of the World War I models. Professor Schwerd once again played a role in creating the prototype; and Eisenhuttenwerke of Thale undertook preliminary testing and prototype design. The Supreme Command of the Army officially accepted the helmet on 25 June 1935. The M1935 was intended to replace all existing helmets in service. The basic design was similar to the M1916, although it was more compact and lighter in weight. The helmet was press-formed in several stages using sheets of molybdenum steel.5 separately inserted hollow rivets replaced the large air vent lugs found on World War I helmets. The rim of the helmet continued to be rolled under for a smooth edge. The M1935 received the updated M1931 liner system as well as a newly designed chinstrap. The new chinstrap replaced the older carbine clip and roller-buckle styles found on earlier transitional helmets. Beginning on 1 July 1935, requisitions for the M1935 were placed through the Procurement Office of the Army and Navy located in Berlin; this was the contracting authority that oversaw the acquisition and distribution of all military material for the Wehrmacht. The M1935 was the first helmet worn at the outbreak of World War 11, and many were used until the very end of the war. Nearly 1.4 million M1935 helmets were manufactured in the first two years following its introduction; millions more were produced until 1940, when changes to the basic design were introduced and production methods changed. Despite modifications to the steel shell, German patent records indicate that subsequent versions of the helmet were still referred to by the original patent designation 'Stahlhelm 35'. The Model 1940 steel helmet Almost as soon as the M1935 helmet was put into production modifications to the basic design were underway. These were led by engineers employed by the Eisenhuttenwerke plant at Thale, which continued to be the foremost producer of helmets for the Wehrmacht. Records indicate that on 29 October 1938 design engineer Erich Kisan of the hale facility filed for a patent (No. 1458613, Group 72g, Class 2) that dealt with the elimination of the separate ventilation rivets. The proposal recommended that the air vents be embossed into the sides of the helmet shell instead of being separately inserted; this was partly to save material, and partly due to the belief that the rivet could become a projectile if the helmet were damaged in combat. Interestingly enough, this modification would not be approved by the Army High Command until 26 March 1940. At that time orders were given for the modification of the M1935 into what has been designated the M1940 pattern helmet. The M1940 was produced using an improved manganese-silicon steel. The helmet was also fitted with an improved liner band ring (see 'Helmet Liner Systems' below) that proved more durable and less costly than the aluminium version. Other than these changes, the M1940 remained identical to the M1935. Manufacturing facilities and equipment had to be upgraded in order to produce the M1940, which resulted in a slightly heavier helmet with a more rounded shape as compared to the M1935. Slowly the M1940 helmet began to replace the M1935 in front-line use, although both were seen in parallel until the end of the war. Stockpiled liner parts and rivets intended for the M1935 were often incorporated into the M1940 until depleted or superseded by updated supplies. The flared-rim M1942 helmet was ordered into production on 6 July 1942 in order to streamline the production process and lower costs. Helmets produced after 28 August 1943 bore no factory-applied Insignia. The Model 1942 steel helmet The last wartime upgrade to the standard helmet was ordered on 6 July 1942 as part of an overall restructuring of Germany's wartime industrial programmes. At the request of the Army High Command, the rolled edge found on M1935 and M1940 helmets was discontinued as an economy measure. On 1 August 1942 the first M1942 helmets were placed into production. By this time, the standard helmet was now made in four basic steps by hot-stamping steel into the desired shape; the older process of press-forming the shell, in combination with oven-heated tempering, had now been replaced by a faster and more efficient method. Many M1942 helmets bear the signs of rapid hot-stamping, as demonstrated by rippled stress marks in areas where the steel is shaped to form rounded corners. The M1942 was mass-produced until late 1944 and early 1945, when most facilities were overrun by Allied armies, or simply left idle by the lack of sufficient materials for continued production.