The era of “modern helmets” finds its roots in World War I with the increased lethality from the use of artillery and resultant fragmentation threats. Steel helmets were introduced in Europe in 1915, and while they did not protect against rifle bullet penetrations they offered casualty reduction benefits that warranted issue and use.
During and post WWI the material science of helmets design continued to evolve, resulting in the introduction of Hadfield Steel Helmets with improved protection levels. The U.S. Military introduced the M1“steel pot” helmet in 1942, which utilized Hadfield Steel construction. The M1 helmets were standard issue through the mid-1980s. More