Hydraulic fitting ID

[PeteN]

I have this style of hydraulic hose fitting on a Titan implement and want to change out the hoses. I don't seem to be able to nail down exactly what form this is. I think it is using the NPSM thread form and seal but it doesn't match up with the specs I have found. The ID of the external threads is 0.635" and I haven't found a thread pitch gauge that fits exactly. 20 threads/in is close but so is 18 threads/in. A 5/8-18 nut will not thread on this fitting but is close. None of the metric thread gauges that I have are even close. Any insight on this?

Update: Looking through my Machinery's handbook I think there is a possibility that it is a British Standard Pipe Thread. There is a size with a 19 threads/inch thread pitch which would be just about right. Amazing they would make thread pitches so close together with different standards.

 

[ptsg]

It's a 3/8" BSPP fitting. BSPP stands for British Standard Pipe Parallel. The taper is 60 degrees.

The thread is 3/8" 19 TPI, although, being a British thread, it's actually a 55 degree thread instead of the 60 degree used on most of the other thread types.

 

[PeteN]

Even better. While I was updating my post you already had the answer. Thanks.

 

[Smokeydog]

Kubota has some British hydraulic fittings too. Some high wear or easily damaged hoses I’ll get adapters so the hose is more easily sourced and much cheaper.

 

[WranglerX]

Then there is this...

 

[WranglerX]

Kubota has some British hydraulic fittings too. Some high wear or easily damaged hoses I’ll get adapters so the hose is more easily sourced and much cheaper.

So does smaller Massey Ferguson... And probably any tractor manufactured off shore (Thailand)...

 

[ptsg]

Pretty much everyone else in the world uses either BSPP, Metric (DIN 2353) or both. It's like the metric/imperial thing all over again.

I'm a bit surprised these fittings are still some what hard to find and expensive in the USA giving how common those are.