M1's And Stress Cracks

[RememberThe5thESB]

While the importance of this may be minimal, I have always heard in the past that a way to determine the age of an M1 very easily, visually, is by stress cracks. Particularly early WW2 production M1's. The reason I've heard being because of the type of metal used in production.

 

But this is not necessarily true as many probably already know, I just felt the need to make this post for any other young collectors such as myself who might have heard these things before. The reason these helmets crack is due to the shape they are, after blanks were pressed to shape, plenty of stress was placed on the metal, over time eventually they give way. And they dont even have to be all too old for this to happen.

 

I picked up my first M1 thinking it was WW2, because it was lined with stress cracks and had a stainless steel rim. But in actuality it was an RJ Stampings, which I will show here. (With about 7 cracks give or take. So many it almost seems defective.)

 

Again the reason for this post was to settle the dust on a little "rumor" I suppose, that I heard while in my younger collecting years, in the hope that someone doesnt make the same mistake I did. And I hope it helps!

 

Sent from my SM-J327V using Tapatalk

 

 

[milsurp_scout_14]

I've certainly run across several Vietnam and post-Nam era M1's that have cracks. Good point to make.

[themick]

Good thread here. I've assumed that when manufactured and inspected, a helmet with stress cracks would be rejected. Thus, the helmets we now see with stress cracks are those where the cracks only occurred over the years, and by now, even with Vietnam helmets, that is a lot of years. I must admit in reference to Milsup's post, I've never seen a Vietnam helmet with a stress crack. I've learned something. So, back to my first thought - if a helmet had stress cracks in the factory, it would have been rejected. Is that a fair assumption?

 

Steve

[Burning Hazard]

A lot of stress cracks I've seen on M1 helmets were due to stacking; the ones on the bottom got the brunt of the weight and the steel would eventually give way.

 

Pat

[RememberThe5thESB]

Never thought about the stacking part, but I can see that being very likely. Especially considering the steel (they're made of steel correct? I've never been too keen on if M1s were steel or magnesium, or iron?) Is already under stress from being pressed into form, and assumingly hardened in some process. All the weight from the helmets above would certainly manage to crack the steel if it was brittle enough.

 

And yes I would assume the pots with cracks would be defects... Wearing something like that in combat would not only provide less protection, it probably wouldn't be good for morale to wear a half cracked egg on your head!

 

Sent from my SM-J327V using Tapatalk

 

 

[Theriddler]

I’ve found that helmets manufactured by the Parish Division of Dana and RJ Stampings are particularly prone to stress cracks.

[Simon Lerenfort]

Nearly all the ground dug M1's I have found have stress cracks, I put this down to reaction between the steel and the damp, soil conditions as much as the steel wanting to return to its original flat state pre pressing.

[MattS]

Never thought about the stacking part, but I can see that being very likely. Especially considering the steel (they're made of steel correct? I've never been too keen on if M1s were steel or magnesium, or iron?)

 

Hadfield Manganese steel, here's a study done in 1945 on the topic: https://apps.dtic.mil/docs/citations/ADA954973

[MattS]

Also keep in mind that M1 helmets, over the course of their 50 years of service, were subjected to being dropped, cooked in, filled with water, used as a seat, shot at, used to beat tent stakes, thrown, and abused in numerous other ways all leading to stress cracks. They left the factory in mint condition, but by 1990 the ones we wore were well used and abused.

[ghengus]

Dont know if this helps but can confirm that M1s with excessive stress cracks were rejected. Here is a FS FB that is stamped War Reject due to the large stress crack in the front.

[3rdMarDivMP]

Several years ago, I took an M1 outside for pictures in natural light. I mistakenly left the helmet in the hot Texas sun for about two hours. When I retrieved it, not only was it too hot to touch but it also had an obvious stress crack that I did not remember it having. I checked the pictures I had taken hours before and sure enough, no stress crack.

[Justin]

Several years ago, I took an M1 outside for pictures in natural light. I mistakenly left the helmet in the hot Texas sun for about two hours. When I retrieved it, not only was it too hot to touch but it also had an obvious stress crack that I did not remember it having. I checked the pictures I had taken hours before and sure enough, no stress crack.

How many and how badly?

 

That's interesting, any photos?

[RememberThe5thESB]

That's odd considering the amount of heat you'd need to make the steel malleable enough to crack under the stress it had. While not impossible though, I'm wondering if the paint had something to do with masking an already existing crack, and becoming more brittle from the heat it shrunk around that crack which, per say was maybe not visible to the naked eye at the moment, and revealed it?

 

Very interesting though and some pics would certainly be appreciated!

 

Sent from my SM-J327V using Tapatalk

 

 

[Bugme]

Several years ago, I took an M1 outside for pictures in natural light. I mistakenly left the helmet in the hot Texas sun for about two hours. When I retrieved it, not only was it too hot to touch but it also had an obvious stress crack that I did not remember it having. I checked the pictures I had taken hours before and sure enough, no stress crack.

????????

I am somewhat skeptical and would certainly need more convincing like the afore mentioned before and after photos.

 

Stress cracks during WWII production was the result of the cold pressing of the M-1's being done too fast. This was resolved with an additional step. This was more dominant in the first year of production and significant stress cracking occurred near the brim as well as across the back. Age cracking is less significant and could be found on helmets manufactured throughout the war. I can't speak for 'nam era M-1's and I don't know that I've ever seen one since my interest in M-1's ends with the low dome but, it would not be surprising.

[trenchfoot]

I have seen a few Vietnam era helmet shells with stress cracks, most of them victim of helmet stacking, so I don't think stress cracks can accurately date a helmet shell.

[RememberThe5thESB]

I know, but I suppose at this point you could call it a helmet myth. I had always heard that if the helmet has cracks it was older, WW2 old. I was younger than how young I am now and took it to heart. I just posted about this so anyone else who may be as naive about it as I was doesnt make the same mistake. It's a "debunking" I guess lol.

 

Sent from my SM-J327V using Tapatalk