M-1 Helmet Production Breakage IV
Metallurgy, Fabrication and Residual Stress
Heat-treating steels for maximum hardness is a delicate scientific process requiring precise supervision to avoid weak pockets in the final sheet stock whereas cold working Hadfield’s manganese to the same level of strength makes this unnecessary.
M-1 Helmet Shaping Operation III - Visor Spanking
The spanking operation bent the visor of the helmet back down in the opposite direction of the initial draw.
M-1 Helmet Production Breakage III - Understanding Why Helmets Cracked
A brief review of how “residual stress” in a finished helmet body was affected by a combination of poor-quality steel, poor manufacturing habits and the design of the helmet.