Safe or not - Male Foster Fitting Bearing Wear

They’re cheap, I wouldn’t use it..get another 

Just because it is magnetic does not make it poor quality. Remember most of the pressure tubes on our airguns are steel and they have been good for decades thus far. Stainless is usually softer than than the steel alloys used in our airguns unless it is hardened. I would guess that someone made that part out of the wrong material or the material was not what it was spec-ed out to be.

I would replace both pieces of that foster fitting just to be sure things are right.

Something else, when you pull the end cap bac from the female part there are bearings that are exposed , A little moly grease helps out loads, If them balls get dry or up use silicone grease You still have time to fix it.

I did,,,

Safe or dangerous? Highly magnetic so I assume not stainless. Note the female foster ball bearing wear and indentions to the point of almost curling some of the metal back. Used after DIN to foster fitting on my LC-110 for tank filling so it is exposed to 250+ bar until 4500 PSI for some time during filling.

Dangerous or normal?

Click to expand...

Stainless is still magnetic. It's not pure chromium, there is still iron in the mix.

This is a pet peev of mine. No not safe, replace it. Female socket is part of the culprit. Should be a 6 ball socket with proper tolerances. The best male fittings are Ninja, because they are properly heat treated. They are competitor to one of my business ventures and I still only use their male fittings on my personal equipment and all the test equipment in the shop. FOSTER the company whose standard everyone copies only has 1 version in this size that is rated to 4500, theirs are fine I use them too. The chinese fittings are using 8mm spec instead of the real size. Thats why the chinese sockets fit everything bit the American and Foster sockets don't fit the Chinese male fittings. It all fun and games until a fill hose pops off and smacks you in the face. One near miss was enough.

Now we have proof of what I just posted. Notice what happened to the female socket.

https://www.airgunnation.com/topic/protective-blast-cage/page/2/

I don't want to be a downer or keep anyone from saving money but HPA fittings aren't the thing you want to save money on. Think how fast and hard you can smack someone in the head with a fill whip. Now multiply it by 100 or more for 4500psi rocket acceleration. Thats why you want your fill whip (notice the word whip) as short as possible. Not only to save air but also minimize impact at catastrophic failure.

I have been using the Ninja fittings exclusively for many years now. They are American made, and actually fit together well always, and as yet I have never had a single problem with the few I am using over many years. 

I had allot of trouble getting the Chinese stuff to fit together and not to leak. Seems like everyone was making them a little different so you had to buy from them to get them to fit together. But vendors just sold whatever they wanted so they often did not fit together even when they came from the same vendor. The female fosters need new o-rings every few months as well. It really sucked for a couple of years until I found the Ninjas.

I had to be a bit creative to fit the Ninja fittings to the Chinese fittings just so I could fill my tanks and guns. Also my compressor and filters are all Chinese so I have been unable to changeover to the good stuff and likely never will.

Think I am just going to leave it metric, change it all to stainless and hope it is a little harder than the brass.

This is the fitting on my Crown after a couple years of use. I was having trouble getting the QD to go on and upon inspection I found it was really getting deformed. Last thing I want to be doing is staring at the gauge on the bottom of the gun when it pops off at 250 bar. Fill nipple next to the gauge always seemed like a bad idea to me. Much rather have a gauge 90° away from the fill.
Some scary stuff in that link!

i think if it wears like that the fitting was 'not' mating correctly in the first place .. just the oring should about hold the fitting in place NOT the ball bearings but if the fitting is tight and you have to push extremely hard and struggle to get the collar locked the fitting is to put it bluntly 'fcked up' it is NOT seating fully and your struggling with the collar to yank it down and relying on that to hold it .. that is gonna eventually result in you hurting yourself when it blows off.. you need to fix it so it fits right or use different hardware ... a foster should go on easily with the collar pulled back then released, then a slight push forward should cause an audible click of the collar into place almost effortlessly, all you are overcoming is oring resistance on the end of the foster NOT metal parts that dont fit correctly .. fix that ...

Some late info on these fittings.

The females come with four, five, or six bearings.

Although most say they are rated for 4500psi I would guess that the units with more bearings would distribute the force more evenly and cause less damage to their male counterpart.

But with that said the male fittings need to be made of the right material and hardness as well.

No matter what they are made of they will all eventually wear so inspect them frequently to stay on the safe side.

Where are you buying the Ninja fittings?