i agree,,,i have several ww II US helmets that have no markings whatsoever on the inside,,
Thanks Bugme, Militarymania and Nick. I've carefully looked on the outside and there is no sign of a helmet shell stamped number. This helmet which spent the past 50 years gathering dust on the top shelf in the laundry room must be one of the select unnumbered M1 variations.
well numbered or not its still a great helmet with good history thanks for sharing
Sorry if this is just me but I always thought that the numbers were are after the shell was pressed, as the actually stand for the heat treatment (tempering) of that helmet batch, the reason is Hadfield steel work hardens in the press tool as its drawn into the shape of the finished helmet, since the steel has been hardened by the pressing and drawing process it only requires tempering. Apparently this is one of the reason why early M1's suffer very badly with stress cracks and hairline fractures, due localised distortion resulting in high stressed areas in the steel caused by the deep shape and curve around the neck region of the shell.
Nige.
"Now, I've designed this like a collapsing bag ! "
the heat stamps as far as i know were done before pressing as not only is the number not always in the same place each time meaning it depends on how the sheet of metal was put in the press but its some times missing as well & i would think it would be hard to stamp it after due to the shape as most of the time its right on the curve of the peak area.
yep Nick that make sense, I just thought as the tempering would have been done after the pressing stage, that heat treatment number would have been then added, unless the "heat treatment" number is not that at all but a stock code or batch number relating to the composition of the steel itself i.e. so if stress fracture or manufacturing faults occurred in that batch of helmets they could track back the source of the manganese steel and therefore see if the fault originated from the metal.
Nige.
"Now, I've designed this like a collapsing bag ! "
Your right on both counts Nige, the number was a batch code to designate when that particular batch was heat treated. Hadfield Manganese(the metal used on the M-1) is a metal that becomes even harder as it's pressed. In metallurgy it's called: Work Hardening. It was the combination of the "Heat Treatment" and the "Work Hardening" that led to the stress cracks that were seen on many fixed loop helmets. Eventually they worked out the combination and later war helmets did not have this problem. The heat numbers are a good(not great) indicator of date of manufacture for the helmet. If the steel was used as soon as it was delivered to the factory, the date would be close. If the steel sat for some time, then the dating was off.
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