Here is a salty lid. NS64 single decal Heer. Suffered a crack somewhere along the way. Still a nice looking lid, I think.
Here is a salty lid. NS64 single decal Heer. Suffered a crack somewhere along the way. Still a nice looking lid, I think.
a nice well worn m40, i like the ns decal
regards Paul
Thanks Paul. The decal has lost most of its toned lacquer but the decal still retains a good amount of the detail.
Those concussion cracks tell a tale don't they!
Sometimes the cracks are from being under extreme temperature changes such as in ice. This doesnt appear to have been buried in the ice though. so concusion could be the case!
When you look at the movies showing helmet production ( and know a bit about toolmaking ) a lot becomes clear. The helmets must have been made from a carbon steel ( not a vanadium steel as used in other load bearing metals ) with a greater than 0.2% carbon content ( so they could be hardened )
Looking at available footage, this is what I think the process must have been..
1) The circular blanks are cut and dipped in soluble drawing oil.
2) The drawing process takes place - this is in 3 stages as the depth of the hemet is too much to be done in one step.
3) The trimming would have been the next step and then the folded edge. This was done by hand then with a bead roller.
4) THen into the oven to 1000 deg for stress relieving from the deep drawing process and re-hardening - then an oil quench ( by the looks of the flame )
This hardening allowed the lid to pass the ballistics testing but the trade-off of hardness is a degree of brittleness. BOTH concussion, frost AND just soil expansion / contraction is the reason for cracks in helmets I feel........
Cheers, Dan
Interesting lid, I used to own a M40 with a concussion crack in the top of the dome. Otherwise it was in very good condition with most of the decal intact.
Regards,
Jerry
Whatever its just an opinion.
Great lid with a ton of character and a nice decal.
Jason
This helmet is for sale in the classifieds. Always open to offers.
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