I'm trying to fit a hose barb to an autometer mechanical vacuum gauge (I want to use silicone vacuum hose vice that crappy hard nylon hose w/ compression nut). As far as I can tell, the autometer sensor is 3/8" MPT, with 28 (possibly 27) threads per inch, and I need a 1/8" ID hose barb. Searching on line for brass fittings, it seems impossible to find a 1/8" id hose to 3/8" FPT connector. just about any 1/8" ID hose barb connector I find only goes to a 1/8" FPT. Does anyone have super secret information on a brass fitting site that has what I'm looking for?

You need a 1/8" x 3/8" NPT bushing.

 

GD

You need a 1/8" x 3/8" NPT bushing.

 

GD

 

The problem with that is that it greatly increases the length of the hardware out the back. I'd rather have all-in-one.

If you get the right bushing it should only increase it by 1/8" or so - and you can file down the hex end of the bushing to shorten it.... then you can cut off a bit of the end of the hose barb.... you can make it work. I doubt you will find a 3/8" barb fitting. They usually skip that size. Why doesn't autometer include one or have one you can buy that's plastic or something?

 

Another idea - you could make a flush-mount bushing with a bit of brass stock, some drilling, tapping, and threading..... wouldn't be too hard. Just do the ID first - thread the brass 1/8" barb fitting into it, then cut the OD threads with a die.

 

GD

Edited July 9, 201114 yr by GeneralDisorder

Thanks. Yeah, I could fit something together. I was just hoping someone might have seen the miracle piece already assembled.

Call Fittings Inc. out of seattle. They dont up charge either. I'm amazed at their selection.