JIC fitting size?

[banjodunn]

G'day an easy way to check a JIC or UN O Ring fitting is the thread is unf so if a 9/16 unf nut will screw onto the fitting then it is a number 9 jic and sizings are done in 1/16th increments so if a 5/8 nut fits then it is a number 10 fitting and so on


Jon

 

[LD1]

G'day an easy way to check a JIC or UN O Ring fitting is the thread is unf so if a 9/16 unf nut will screw onto the fitting then it is a number 9 jic and sizings are done in 1/16th increments so if a 5/8 nut fits then it is a number 10 fitting and so on


Jon

Not correct at all. The dash size refers to the inside diameter. Kinda hard to have a 5/8" inside diameter with 5/8 outside fittings.

A 1/2" fitting (-08) has 3/4" threads. And 9/16" threads = 5/16" (-05) fitting. (there is no -9 fitting BTW)

 

[UniversalHosman]

I wouldnt even attempt an educated guess on fitting size based on hose size.

It seems fairly common (at least on my equipment) that the fittings get upsized by 1. Not so common in the industrial places I have worked.

My backhoe is full of 3/4 hoses and 7/8 fittings.
Dads backhoe is 5/8 hoses and 3/4 fittings.
His international loader is 1/2 hose with 5/8 fittings
My kubota loader has 3/8 hoses with 1/2 fittings

I work with hydraulics about every day. I cannot tell the difference between a 7/8 fitting on 3/4 hose vs a 3/4 fitting on 3/4 hose by just simply looking. I still measure to confirm. So I wouldnt even try to think someone with less hydraulic experience be expected to get it right.

Yeah I shoulda left out the 1/2" - 5/8" comparison and maybe the hose vs fitting comparison altogether. Even with a good eye this may not be easy. On the other hand, I tend to cringe when someone on the other end of the phone starts telling me what they "measured". Sometimes we can tell something if they can get a wrench on the nut. That can be fairly reliable when working with JIC fittings. That said, I don't think it hurts to at least look. Sometimes something obvious might rear its head. I've done it because it can be difficult to ID a hose over the phone.

Andy

 

[myyaz33]

Well, the 1/4 JIC fittings came today and I was WRONG... WRONG... WRONG... The ones I bought are too small so I remeasured with the caliper. The results are posted below. I have no idea how I screwed up but I sure did and it even appears the flares are different. Looks like I will be needing to return most everything I bought. Not sure if they will take hoses back. This will set me back another week on getting the grapple finished.

Here are the new measurements for the loader fittings I still need help with.
ID- .438
OD-.498

My next post has pictures of the old fitting by the 1/4 JIC ones I purchased.

 

[myyaz33]

Still need help identifying the correct size.

 

[LarJea]

Before you reorder fittings make sure the thread size is UNF and not MM. JIC fittings use UNF with 37 degree cone. JIS or Komatsu fittings use metric threads with a 30 degree cone. Also the Chinese use a 37 degree fitting same as JIC but with metric threads called a 74 degree cone but is very rare here in America....I know because I wound up with a hydraulic control valve with these fittings installed and had to use adaptors to make it work.

 

[LarJea]

Also I forgot to add that you can just buy JIC female/male JIC adaptors that will fit over your 1/4" JIC to go up to what ever size JIC fitting you need. You might want to look at a JIC size chart so you know you are getting the right size.

 

[LD1]

-5 JIC

OD of the threads is supposed to be .500. You got 0.498. the difference is the thickness of a human hair. Certainly within the margin of error.

Since hoses are custom cut/made, you may still be able to use them. Just the adapters

 

[myyaz33]

If I just use adapters should I have any concern that the opening on the jic-4 fitting is smaller than the fittings already on the loader curl. I don't want to slow the curl down, it's already to slow.

 

[BukitCase]

Yes you should - keep in mind that area of a circle isn't linear relative to diameter - if you reduce diameter by 1/2, you'll get 1/4 the flow at same pressure. Looking at your pics, I'd guess the flow difference between the two would be just about DOUBLE... Steve

(a diameter change of 1.414 up or down is double or half the area)