Body armor shelf life

[TTv2]

Firstly, I don't want any "why do you need body armor" questions. I probably don't need it, I want it, end of discussion. I want to focus on facts, not my personal situation.

I'm looking at buying some plates for myself and when I look at AR500's website, steel plates have a 20 year life, but the Polyethylene armor, that weighs a lot less, is only 5 years.

For those with more experience and knowledge than I, why is the shelf life so low? Does the shelf life mean that one day past expiration that it will fail to stop a bullet?

I would like to buy the lighter weight armor, but if it requires being rotated every 5 years, the cheaper steel plates are a lot more sensible to me.

 

[lemaymiami]

I suspect that "shelf life" is much more something devised by lawyers than any real deterioration on such items - but I'll wait to hear from others that might be more specifically knowledgable on this topic....

I wore body armor daily for almost 22 years - and really appreciated the day when it was no longer necessary. Down here in south Florida wearing body armor took some doing...

 

[edwardware]

From an engineering point of view, oxidation changes the properties of both steel and polymer armor.

The 20 year shelf life on a steel plate is pretty silly. It won't last forever, but if you don't let it rust it'll outlast you by a century. Consider the condition of steel structures where the steel is protected from the weather.

The polymer is more interesting. It's oxidizing at a measurable rate as soon as it pops out of the mold, and never stops. Cool, dry, dark, and low ozone concentration will slow, but not stop, that process.

In both cases, the manufacturer probably set the shelf life so that they could be absolutely sure than there would be no degradation in performance, no matter how abusive the conditions.

 

[Slamfire]

This is a good thread on the subject: https://thefiringline.com/forums/showthread.php?t=270661

I do believe the five year shelf life is subjective, from what I have read on the subject flexing, heat, humidity deteriorate the plastic. We have here material and polymer scientists, maybe they could comment on the general nature of deterioration of a thermoplastic or thermoset polymer.

These ballistic materials are fibers in a resin matrix. The combination of both provide the barrier. Maybe flexing breaks the adhesion between the two, possibly also causing cracking on the fibers, which I assume are continuous fibers. Why anyone would use a resin matrix that deteriorates with water, heck if I know, because humans are mostly water, and sweat water.

 

[Odd Job]

The 20 year shelf life on a steel plate is pretty silly. It won't last forever, but if you don't let it rust it'll outlast you by a century. Consider the condition of steel structures where the steel is protected from the weather.

The polymer is more interesting. It's oxidizing at a measurable rate as soon as it pops out of the mold, and never stops. Cool, dry, dark, and low ozone concentration will slow, but not stop, that process.

In addition to that, some companies factor in a certain amount of wear and tear.
My advice is to contact the company directly and find out why they have that shelf life. Also, be sure to find out what their recommended testing schedule is. I know for the ceramic plates some police departments get them X-rayed. I don't know how they test the other materials (other than a visual inspection).

This thread has some interesting info about ceramics:

https://www.lightfighter.net/topic/ceramic-armor-plate-xray

 

[ColtPythonElite]

Soft armor wears out from being worn. If you want it for just in case, but don't plan on wearing it until they day you think you need it it will probably last for decades if you store it in a reasonable place.

 

[TTv2]

From an engineering point of view, oxidation changes the properties of both steel and polymer armor.

The 20 year shelf life on a steel plate is pretty silly. It won't last forever, but if you don't let it rust it'll outlast you by a century. Consider the condition of steel structures where the steel is protected from the weather.

The polymer is more interesting. It's oxidizing at a measurable rate as soon as it pops out of the mold, and never stops. Cool, dry, dark, and low ozone concentration will slow, but not stop, that process.

In both cases, the manufacturer probably set the shelf life so that they could be absolutely sure than there would be no degradation in performance, no matter how abusive the conditions.

All this makes me think steel plates are the way to go. If the steel plates can last another 50 years, the polymer likely wouldn't. I think I'd rather go steel now because maybe 10 years from now carbon fiber prices will drop or Titanium processing will improve and they'll become viable options for body armor plates and weigh a lot less.

 

[MidRoad]

Assuming you are just a citizen (not a cop, or contractor,military, etc) I would think the weight difference between steel and the plastic stuff should be the least of your worries if you find yourself in a situation that requires body armor.

Go steel, don't worry about a shelf life, and hope it'll just sit on a shelf and never be needed.

 

[ATLDave]

I don't know anything about this topic, but the idea of a "best by"/expiration date on a piece of steel makes me laugh. I wonder if the local hardware store has to rotate their stock of bolts so that the older ones are in the front and get bought before they spoil...

 

[MidRoad]

I don't know anything about this topic, but the idea of a "best by"/expiration date on a piece of steel makes me laugh. I wonder if the local hardware store has to rotate their stock of bolts so that the older ones are in the front and get bought before they spoil...

I thought the same thing

 

[Wisco]

In 2015 I shot up some IIA soft armor that expired in 2004. It was Second Chance brand, I believe.

The small side panels stopped 22LR and 32 ACP. The front panel stopped 9mm NATO, including several hits close together. The back panel stopped 45ACP ball. After the pistols, I shot it with 3inch 00 Buck and the armor stopped it.

This was all at less than 10 yards.

The panels were flat against plywood and the wood took a beating...but no punctures.

Don’t take this as a scientific study - it was one old set of armor against mostly ball ammo just for giggles.

I would be comfortable with quality IIIA soft armor and level IV ceramic plates within 10 years of manufacture that were stored appropriately and not used often.

If you buy steel, make sure you get appropriate backing and fronting for them - don’t want to take rifle rounds to the chest only to be taken out by bullet splatter to your face.

 

[TTv2]

I don't know anything about this topic, but the idea of a "best by"/expiration date on a piece of steel makes me laugh. I wonder if the local hardware store has to rotate their stock of bolts so that the older ones are in the front and get bought before they spoil...

It wasn't the steel I was concerned about, it was the polymer plates AR500 and other companies make.

 

[TTv2]

If you buy steel, make sure you get appropriate backing and fronting for them - don’t want to take rifle rounds to the chest only to be taken out by bullet splatter to your face.

Is this the Paxcon coating that AR500 offers as an add on?

 

[ColtPythonElite]

I was issued both. Steel is very heavy. It doesnt wrap around like soft armor for 360 protection....at least mine didn't.

 

[Wisco]

Is this the Paxcon coating that AR500 offers as an add on?

That, I’m not sure. If it offers protection from splatter, that’s what you want.

I haven’t priced them myself as I have a set of ceramic, but how much is good steel versus multi-strike ceramic for level IV stand-alone?

 

[milemaker13]

Baby seats made from plastic suddenly become unsafe the day after they 'expire' just like the soft armor.

Like others said: lawyers, CYA, worst possible case and sell more!

 

[hdwhit]

ATLDave wrote:
I wonder if the local hardware store has to rotate their stock of bolts so that the older ones are in the front and get bought before they spoil...

If the hardware store was selling the bolts for critical service applications where the consequences of failure to environmental degradation were catastrophic, yes, they would rotate their stock. There are fasteners used in aeronautical and aerospace applications that have expiration dates on them just like a jug of milk.

 

[hdwhit]

TTv2 wrote:
For those with more experience and knowledge than I, why is the shelf life so low?

Edwardware already provided an excellent response in post #3.

Does the shelf life mean that one day past expiration that it will fail to stop a bullet?

No, it will not spontaneously disintegrate on day 1828 (allowing for the 5 year period to have two leap years).

What it does mean is that the manufacturer has a high degree of certainty that even in a rough environment, the plate will do what it was designed to do for at least 1827 days. After that, they can stop accruing a liability on their books to cover the cost of you suing them if the plate doesn't work.

 

[Zaydok Allen]

From an engineering point of view, oxidation changes the properties of both steel and polymer armor.

The 20 year shelf life on a steel plate is pretty silly. It won't last forever, but if you don't let it rust it'll outlast you by a century. Consider the condition of steel structures where the steel is protected from the weather.

The polymer is more interesting. It's oxidizing at a measurable rate as soon as it pops out of the mold, and never stops. Cool, dry, dark, and low ozone concentration will slow, but not stop, that process.

In both cases, the manufacturer probably set the shelf life so that they could be absolutely sure than there would be no degradation in performance, no matter how abusive the conditions.

I'm not an engineer but this mirrors my sentiments on the subject. My hard hat has an expiration date on it because some if not all plastics will become more brittle with age.

A freshness guarantee on steel? Come on........... As edwardware points out, if you take care of it, 20 years is a silly number.

 

[BLB68]

Baby seats made from plastic suddenly become unsafe the day after they 'expire' just like the soft armor.

Funny, just the other day I was listening to a piece on the radio about this. The upshot was that small plastic pieces could degrade over time, like fasteners, buckles, etc., so it was better not to buy a used car seat that was past its expiration date. This makes sense, because plastics break down under high heat and direct sunlight. The actual date is probably the manufacturer's best guess, and probably the worst case scenario.

The dates on the armor plates are probably also based on some worst case scenario.

 

[lemaymiami]

...and now that we've had a few responses - here's what I told my young cops about body armor.. the best body armor is worthless unless you always wear it - no matter how bad the conditions are at the time (Miami in August is a great bad weather example, for instance...). Learning to live with the gear (and put up with the odor...) isn't easy - but do-able for most -if they really want to have the protection. Are there some that simply can't tolerate body armor? Absolutely (particularly big guys...), but if you can live with it you just might have it on -that one time when you really, really need it...

By the way, from an old cop's point of view.. the one statistic I've never seen is the number of terrible woundings or fatalities -that were wearing body armor when the deal went down. In my area (I always counted Dade and Broward counties, Miami to Ft. Lauderdale as a single unit since it was a continuous urban/suburban area for about seventy miles...) we lost three badges a year, every year for all of my 22 years on the street (none of that includes bad personal habits, or angry wives or girl friends...). I'd say, from memory, that about a third of our shooting fatalities were wearing body armor the day they died. All body armor does is give you a chance to respond - after you've been hit, center of mass. Hits from the side aren't protected - nor is any portion of the neck, head or groin areas... Something to remember for any going in harm's way here in the good old USA.....

Me, I'm very glad my old armor has been hanging in the closet these past 22 years - and hope I never have to put it on again...

 

[shafter]

Keep in mind that no matter which you decide to buy, you will need to train with it if you expect to be able to fight with it. Steel plates are heavy and bulky. If it doesn't fit right you may find it difficult to extend your arms for a two handed grip on your pistol.

 

[Al-jim19]

No source I have read has suggested real world failure of expired body armor of any kind. In fact, all sources I have ever read reported performance on par with unexpired plates. The idea that AR500 steel will expire is laughable. It may rust if it’s uncoated, but if you add the spall coating to it there’s almost no chance of that. I know little about polyethylene but my hunch is that on year 5, day 1 it will still stop a bullet. Check out bulletproofme.com for some info on expired armor tests. YouTube also has a number of good videos.

Something else to consider is the weight of the armor. Steel plates are easily 8lbs or more each. With the necessary spall coating maybe more. A pair of those plates will run close to $200 if you don’t skinflint the process. Considering the price, ceramic level IV plates are a better investment. Again, they do not expire, and a pair will probably cost about $300-$350. They will be much more comfortable and are a better long term investment if you can swing the extra cost.

 

[Stevie-Ray]

Why anyone would use a resin matrix that deteriorates with water, heck if I know, because humans are mostly water, and sweat water.

"Ugly bags of mostly water".........ST:TNG

 

[z7]

if you go with ar500 plates, a reputable company with good spall coating is a must. just go to any range that has steel plate on wood target stands to see for yourself.
I'd rather take my chances with spall vs a gsw, BUT spall may take you out of the fight anyway. I WOULD NOT get ar500 body armor of of Ebay or Amazon. . . .the steel will work but i would spend the extra money to buy from a company that produces a reliably spall coating in the tragic case you ever need it.