jkgts1 Posted April 30, 2009 Share Posted April 30, 2009 The past few days I have been thinking of ways to set up my fuel system for my 260z (2jzgte). Anyway I found some AN steel weld in fittings. Now this might be a silly question, but is it ok to use the steel AN fitting with the aluminum AN fittings? I assume it is okay, due to the fact that I do not see any other steel AN fittings aside from the weld in type. Did that make sense? Thanks Quote Link to comment Share on other sites More sharing options...
WizardBlack Posted April 30, 2009 Share Posted April 30, 2009 The past few days I have been thinking of ways to set up my fuel system for my 260z (2jzgte). Anyway I found some AN steel weld in fittings. Now this might be a silly question, but is it ok to use the steel AN fitting with the aluminum AN fittings? I assume it is okay, due to the fact that I do not see any other steel AN fittings aside from the weld in type. Did that make sense? Thanks Yeah it's fine. Quote Link to comment Share on other sites More sharing options...
jkgts1 Posted April 30, 2009 Author Share Posted April 30, 2009 Awsome, thanks Quote Link to comment Share on other sites More sharing options...
evildky Posted April 30, 2009 Share Posted April 30, 2009 yup, and the steel ones are called JIC by the way, and you cna get them at hydraulic hose fittings shops cheaper than a/n Quote Link to comment Share on other sites More sharing options...
WizardBlack Posted April 30, 2009 Share Posted April 30, 2009 yup, and the steel ones are called JIC by the way, and you cna get them at hydraulic hose fittings shops cheaper than a/n Actually they are classified as JIC 37; which is a bit like an ASTM classification (AFAIK). Any fitting that is classified as JIC37 will have appropriate 37 degree taper and flare type fitment. It is fortunate that all the speed guys use AN stuff as you can get brass and steel from other industries; as you noted. That's why you probably don't see a lot of steel in the performance shops. You can go down to a big hardware store and get brass right off of the shelf for dirt cheap. Quote Link to comment Share on other sites More sharing options...
DeleriousZ Posted April 30, 2009 Share Posted April 30, 2009 beware of the sae stuff, it has a 45* taper. it will work in a pinch, but i wouldn't recommend it. Quote Link to comment Share on other sites More sharing options...
johnc Posted April 30, 2009 Share Posted April 30, 2009 (edited) Bzzzzt! Wrong answer boys! http://www.mechanicsupport.com/articleStronger.html quote from Parker Aerospace Fitting Solutions Series No.11 Aircraft AN fittings are manufactured to MIL-F-5509 per AN (Air Force - Navy Aeronautical Standard) and AND (Air Force - Navy Aeronautical Design Standard). Industrial 37 degree flare fittings are manufactured to meet SAE J514/ISO-8434-2. Straight threads are per MIL-S-8879C now SAE-AS8879. The most notable difference between these standards are in the threads. AN fittings use a increased root radius thread ("J" thread) and a tighter tolerance (Class 3) to achieve a 40% increase in fatigue strength and 10% increase in shear strength (thread tensile stress area of 110.76 compared to 103.20 mm2 ). This difference is stated in the thread designation, For example: AN Fitting: 1/2-20 UNJF-3B Industrial: 1/2-20 UNF-2B These two fittings function the same, they look the same, AND the industrial version is much less expensive to manufacturer. The problem is that the industrial version is 40% weaker. There is a an Airworthiness Directive (90-04-06) involving breaking of the aluminum propeller governor fitting on Lycoming engines. The aluminum AN fitting was used successfully for decades before they started breaking. The justice department brought charges against a company that was selling these fittings as AN when they were in fact industrial. Sometimes the higher strength serves an important purpose. Aircraft are vibrating structures, much more so than most industrial applications. Vibration fatigues the threads, so aircraft hardware uses a modified thread form and tighter tolerance to increase fatigue strength. This is true not only for AN fittings but also for AN and NAS bolts, and installed hose "B" nut fittings. These aircraft hardware items are also UNJF-3A/3B whereas the industrial is UNF-2A/B. Fittings made to AN spec are stronger and more vibration resistant then fittings made to JIC spec. Edited April 30, 2009 by johnc Quote Link to comment Share on other sites More sharing options...
WizardBlack Posted April 30, 2009 Share Posted April 30, 2009 Bzzzzt! Wrong answer boys! LOL Fittings made to AN spec are stronger and more vibration resistant then fittings made to JIC spec. Doesn't mean that they can't be used in certain applications, no? Are you sure every "Earls" fitting or JEGS fitting and other discount "AN" brands actually follow the spec and not just advertise them as "AN Style"? Quote Link to comment Share on other sites More sharing options...
johnc Posted April 30, 2009 Share Posted April 30, 2009 Doesn't mean that they can't be used in certain applications, no? That's your decision, I'm just providing information. Are you sure every "Earls" fitting or JEGS fitting and other discount "AN" brands actually follow the spec and not just advertise them as "AN Style"? Don't know, you'll have to contact them. Quote Link to comment Share on other sites More sharing options...
WizardBlack Posted April 30, 2009 Share Posted April 30, 2009 That's your decision, I'm just providing information. Good to know! Quote Link to comment Share on other sites More sharing options...
menzzer37 Posted May 4, 2009 Share Posted May 4, 2009 Knowing the tensile strength of the steel though, I doubt there will ever be a datsun situation that produces forces anywhere near yield. I think the .4 ratio will be fine for this. Quote Link to comment Share on other sites More sharing options...
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