Hydraulic hose problem

[k0ua]

OK, what is this fitting, really.

Dixon 2404-12-12 Zinc Plated Steel Hydraulic Fitting, Adapter, 1-1/16"-12 NPT Male JIC 37 Degree Flared x 3/4"-14 NPTF Male | AmazonSupply.com

That there is a terribly mislabeled connector. Nothing in the description matches the picture or even makes sense.

 

[Discount Hydraulic Hose]

OK, what is this fitting, really.

Dixon 2404-12-12 Zinc Plated Steel Hydraulic Fitting, Adapter, 1-1/16"-12 NPT Male JIC 37 Degree Flared x 3/4"-14 NPTF Male | AmazonSupply.com

What you have is a #12 Male JIC (3/4" tube diameter and a 1-1/16 thread diameter) and a 3/4" Male NPTF on the other end.

The error was in someone thinking that JIC is a pipe fitting, and adding NPT to the description of the JIC Male connection. Once you remove that, it becomes more clear.

By the way, Amazon is asking $7.27 for that fitting, and it's only $1.33 on our site.

Steel Fittings: JIC 37° Male x NPTF Male Pipe

 

[Discount Hydraulic Hose]

And why would that be? It is perfectly mated to the fitting you just unscrewed it from. Both parts have deformed into compliance. ... You can use those parts together again with no problem. Alternately, it seems if the joint had been overtightened both sides would be damaged and substitution of new in either side would be a problem.
larry

I'm not an engineer, but the phrase "deformed into compliance" seems jarring and contradictory to me. The specifications for NPTF are, by their nature, more precise than the specifications for NPT. The deforming process isn't controlled enough to create the kind of compliance that those specifications require. Metal surfaces are rubbed against one another. Scratches and other defects are created. It is illogical (to me) that those defects will result in more strict compliance with the NPTF standard.

The fittings will still work as NPT threads, and will seal with proper application of sealant or thread tape. But, they will no longer form a dry seal, which I believe is part of the intent of the NPTF specification.

 

[J_J]

Is the NPT or the NPTF stamped on all your pipe fittings so as to designate the difference.

http://www.parker.com/literature/tube fittings division/General_Technical.pdf

After some research, I have to agree with KEN at Discount Hydraulic Hose and the guys at Parker hose fittings.

The threads are compatible but the NPT or NPTF may not show on every fitting.

They both need sealant or lock fluid.

Parker says after about 2 or 3 times of use, you might think about replacing them if they start to leak,

A bigger hammer or wrench does not work all the time.