Updated: Sep 16, 2020
Your WWII collection is not complete without an M1 helmet and with roughly twenty-two million made during the war, acquiring one is a very achievable task; you only need to know what to look for. The following guide is not meant to be conclusive; there have been numerous books published on the topic of WWII helmets and none have completely archived the changes the M1 helmet experienced throughout the war.
Two main companies produced the majority of WWII M1 helmets - McCord Radiator & Manufacturing Co., located in Detroit, Michigan and Schlueter Manufacturing Co., located in St. Louis, Missouri. McCord began production in June 1941 and by the end of the war it had produced twenty million M1 helmets. Starting in January 1943, Schlueter began producing its two million helmets. These two producers can be distinguished by multiple features. Firstly, the shape, McCord helmets have a higher top and a slight 'dip' towards the front of their brims, whereas Schlueters appear stouter and maintain a somewhat constant angle from the side of the helmet to the front. Both manufacturers' helmets left the factory with olive drab paint, cork texture, and bartacked web chinstraps. When possible, try to acquire helmets that are still in this wartime configuration.
Two other methods of differentiating a McCord manufactured helmet from a Schlueter can be viewed from the same perspective. The steel rim (stainless on early examples and manganese on later) wraps around the helmet and meets at what collectors often call a "seam." Most wartime M1s have a seam that meets at the front, however the seam was moved to the rear in November 1944 and remained there for decades of later M1 helmet production. McCord helmets exhibit oval-shaped welds at the seam, whereas Schlueters are circular. Additionally, located near the front seam is the "heat stamp", a lot number pressed into the steel shell. Both manufacturers stamped their helmets with a two to four-digit number followed by a letter, but Schlueter also stamped an 'S' beneath their heat stamps.
Heat stamps can be used to roughly determine the production date of M1 helmets. The book Helmets of the ETO includes a chart to date McCord manufactured helmets, however the information is copyrighted. Circa1941 produced a chart (shown below) in order to estimate the production date of Schlueter manufactured helmets. If you would like an updated copy in Microsoft Excel format, feel free to contact us. The red text on the images below notes changes in helmet production, such as the transition from fixed loops to swivel loops.
The earliest produced helmets featured a welded fixed loop upon which the web chinstrap was bartacked. McCord utilized slightly different varieties of fixed loops throughout the war, whereas the shape of Schlueter's fixed loops remained somewhat constant. Notice the circular "feet" and overall arched shape on the Schlueter example when compared to its McCord counterparts shown below.
In November 1943, a new style of chinstrap loop was introduced that swiveled, offering more movement to the wearer and less chance of it snapping at its welds. The image below shows a swivel loop, with its original bartacked chinstrap. Helmets that still retain their sewn chinstraps are quite desirable.
Chinstraps were outfitted with a buckle, J-hook, and end-keeper. Early-war helmets showcased OD#3 (khaki) webbing and cast brass hardware carried over from the M1917A1 helmet, while late-war helmets exhibited OD#7 (green) webbing and flat buckles, although some variations were seen throughout the war.
Now that you are familiar with the steel M1 helmet shell, you will need to find a liner. In early 1941 McCord tasked Hawley Products Co. of St. Charles, Illinois to produce a suitable liner for its steel helmet. The temporary solution was a liner that consisted of two rigid fiber shells cemented together, impregnated with water resistant chemicals, covered with olive drab fabric, and outfitted with a silver rayon suspension. Hawley produced a total of 3,977,000 helmet liners from July 9, 1941 until production ceased in November 1942.