How tight is tight??~AN fittings???

monte87

Founding Member
Feb 26, 2001
876
18
49
new york
Greetings guys-
Just like the title states-
"QUESTION"- How tight is tight when wrenching AN fittings??? I have no experince on these type of fittings, and dont want to strip them. Hand tight and then what? 1/8, 1/4, 1/2 inch turn whats the deal? Its for a FUEL pressure gauge, SS line/hose and all.

Thanks in advance- Anthony:nice: :flag:
 
Hey Man,

I'm an engineer for an aerospace company and our specs are -4 115-130 in-lb, -6 180-200 in-lb, -8 285-315 in-lb, -10 390-430 in-lb. Divide by 12 for ft-lbs. Hope this helps. I wouldn't wrench them to the max torque unless it leaks.

Tom
 
Hey Man,

I'm an engineer for an aerospace company and our specs are -4 115-130 in-lb, -6 180-200 in-lb, -8 285-315 in-lb, -10 390-430 in-lb. Divide by 12 for ft-lbs. Hope this helps. I wouldn't wrench them to the max torque unless it leaks.

Tom

Thanks Tom,

But now in english! hahahahah hand tighten it, and then snug it up what- 1/8, 1/4, 1/2 of a turn???, ft/lbs of torque dont apply, you cant use a TQ wrench. Whatta ya say?

Thanks Anthony
 
Yes you can use a torque wrench, and the specs given to you are what you should use. There is no way you can tell the torque on an AN fitting by how far it turns after the parts mate and snug up.

I spent 11 years as an aircraft mechanic, and tightened more AN fittings than you can imagine. An inch pound torque wrench needs to be part of every serious mechanic's toolkit.
 
If you do not have a torque wrench, then tighten fitting until "snug". The run everything and check for leaks, if it leaks, snug it up a little more. If it does not leak, road test and check again. But they do not need to be tight in the classical sense, I.E. one half turn before it strips. If that does not work, Go buy a torque wrench. You will be glad you did.
 
Yes you can use a torque wrench, and the specs given to you are what you should use. There is no way you can tell the torque on an AN fitting by how far it turns after the parts mate and snug up.

I spent 11 years as an aircraft mechanic, and tightened more AN fittings than you can imagine. An inch pound torque wrench needs to be part of every serious mechanic's toolkit.


I have a TQ wrench, Just dont see how you can get a socket around the fitting??? or stainless steel hose-Help me out with this???
I have zero experinece with AN fittings.........
I mean-I can aply the TQ wrench on the fittings that go onto the shraeder valve fitting, and the mehcnacial gauge itself, But what about the HOSE??? You would have to wrench it with an open end AN -4 wrench, and i dotn see how-You can measure it by hand.

Hit me back, Thanks Anthony:shrug:
 
It is called a crows foot wrench, fits on the end of the extension and then the torque wrench attaches to the other end of the extension. Most parts houses will sell crows foot wrenches. Or you spend big $ and get the Snap-On version.
 
For An fittings I ran myn up tight by my fingers, then maybe a half turn or so with a regular wrench. Turn the bottle slightly open, listen to all bottle fittings for leaks and tighten slightly what needed to be tigthtenend and everything was good to go.