Stainless steel 304 rating only 2570 psi?

Does anyone know the rating pressure for stainless steel 304 fitting? All the fittings im looking at doesn't list the pressure rating. It just says it is 304 stainless steel. I just google it and it says only 2570 psi. I am going to use stainless steel 304 fittings for filling my guns and tanks up to 4500 psi. Is it safe to use to fill my guns and tank?

Another question is, what type of materials is made from our pcp fittings such as the foster quick fill connectors that comes on our pcp guns and tank fittings. Arent they stainless steel and brass? Looks like the male quick disconnect are made from stainless steel while the female side are made from brass. 

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Just to make things interesting in regards to quality. Pressure ratings for NPT threads are based not only on material and thickness but on proper thread profiles. I have gauges for 1/8 npt threads and check the Chinese stuff before use. Confirm thread engagement once assembled (number of turns). Eventually, it's just easier to use Parker or real Foster fittings. 
 
Be VERY careful what and where you buy from ! 

Just a heads up...

Unless you were in the Aerospace or Automotive business back in about the 1980's / 1990's, you may not know this but, MOST if not all "offshore" manufactured nuts, bolts, fittings, washers, etc., etc. were found to be suspect junk. Over a few years, these parts were tested by one or two qualified labs, and found to be...garbage !

Bad thing...It's STILL happening. A nut and bolt shop near me has grade "8" fasteners that are MAYBE, grade "5". If you want REAL grade "8" hardware, the cost goes up about 4 times of the FAKE grade "8".

I talked to one of the employees about it. He said "no way, I didn't know what I was talking about" ! I told him he has no clue what he is selling ! I told him one way to tell, at least good from garbage hardware. I made him a bet. You take your "normal" grade "8" bolt and a "known" manufacturers, grade "8" bolt and do these two tests. He said he didn't have the money for my bet. I told him that if I'm wrong, I'll pay for the two fasteners, If I'm right, he pays for the two fasteners. That's how much he thought I was nuts.

I went in about a week later to see what the outcome was. He smiled and gave me the finger when I walked in !! He said that he was SURE that their normal grade 8 fasteners was good stuff. Now he's pissed that he has to sell crap to customers, and can't say anything..!

I still buy lower classed hardware for low stressed applications there, but if I need known, high quality fasteners, I go to McMaster Carr or Grainger. These guys were asked by the government to sell ONLY high grade, USA made hardware. They complied, years ago. And if you have a few extra dollars, they will furnish documentation as to the authenticity of the hardware.

Mike
 
I werqed for the transit system here in the Portland PDX area for many years. About a quarter of the way through those many years the bean counters decided that they would start using fasteners made in China cuz they cost so much less. We mechanics begged them not to but they won the fight as they often did. 

Some months after these fasteners showed up we started having more failures in many systems on the buses.

Of course we got blamed for all of these problems until we were able to prove that it was the fasteners failing that was the problem. It took many months for us to prove this. Meanwhile we were overloaded with extra werq and some of the failures were becoming dangerous.

When it was over, we got our American made fasteners back and, most of the breakdowns slowly faded away over then next couple of years.

The bad thing about this is once something fails to werq someone always comes up with the bright idea, a few years later, that there was some other reason it did not werq. So, once again four or five years down the line we go though the same thing all over. 




 
Be VERY careful what and where you buy from ! 


I buy all my fittings and hose and even compressor from China and been using them for year up to 4500 psi with no problems. The saying that Chinese products is trash and don't use them. Only use American made item is false. 90% of all air gun and related products is made in China. I haven't seen where these Chinese made guns have exploded and killed someone. You are more likely to get run over by a car then get blow up by Chinese made pcp airgun and compressor.