OIL PRESSURE GAUGE ???

[MIDNIGHT RIDER]

What is the thread size of the sending unit for aftermarket mechanical oil-pressure gauges??

Are they 1/4NPT or 1/8NPT ??

I have easy access to my oil-pressure unit and want to plumb in a tee (plugged for the present) so that it will be easier to hook up a mechanical gauge when time and finance allows.

 

[argve]

All of them that I have installed come with 1/8" NPT along with a bushing to adapt them to 1/4"NPT (bushing comes in the box). If not you can adapt it for less than a dollar at any hardware store (plumbing dept).

 

[sle2115]

Are they 1/4NPT or 1/8NPT ??

Mine are all 1/8 inch pipe. That is what the block is threaded on mine both on top and down on the driver side where I have my gauge sending unit installed.

 

[Agnem]

I hate NPT! How can anything that looks like it's 1/4" in diameter actually be 1/8"?

 

[argve]

inside diameter... that's how... it takes a while workign with the stuff to look at it and know what size is what but after a while you get to the point where you can look at it and know... You would not believe how many folks don't know what size is what when it comes to pipe fittings so your alone... I have worked with guys that have been in maintenance for many many moons and they still have to just cart off two different sizes to see which one fits... heck truth be told I do that... I keep a some in a junk tray in my tool box so I can tell what's what... I have even thought about setting up a little display back in the shop so that we can just screw the fitting into something to tell what size is what...

 

[sle2115]

It is strange that way. The bad part is, about the time you say 1/8 NPT is 1/8 inside diamerter, but the threads are larger, here they come wanting a tubing sized fitting where 1/8 is the outside diameter! Starting to remember why I left the parts business!

Also goes with the "I need a 1/2 inch bolt, coarse thread, 3 inches long" then you show them a 1/2 inch bolt and they say "Wow, that is not a 1/2 inch bolt, it is way to big." Almost always find they were using a 1/2 inch wrench and the bolt is really a 5/16 inch bolt or worse yet, metric!!!

 

[argve]

forgot about the hose fittings... yep keep them confused I think was the motto when these types of things were designed...

 

[John Haggerty]

It's all about the ID. OD has nothing to do with flow. From an engineer.

 

[MIDNIGHT RIDER]

Thanks for the info.

Also, I thought 1/8 inch pipe was 1/8 inch inside diameter; but I slid a 17/64 drill-bit through a 1/8 inch pipe nipple.

 

[RLDSL]

Thanks for the info.

Also, I thought 1/8 inch pipe was 1/8 inch inside diameter; but I slid a 17/64 drill-bit through a 1/8 inch pipe nipple.

If they called it a 17/64 pipe fitting, they'd have to start handing out straight jackets

---------Robert

 

[sle2115]

It's all about the ID. OD has nothing to do with flow. From an engineer.

That may be, but OD is used to determine tubing size. From a retired parts pusher!

Your brake lines are not 3/16" or 1/4" ID! But they could have been marketed by their ID size instead of making it difficult and different from pipe fittings.

 

[sle2115]

If they called it a 17/64 pipe fitting, they'd have to start handing out straight jackets

---------Robert

:draw :draw