Thread sizes: metric? imperial?

jmez1996 · Sun Jul 31, 2011 7:58 am

I live in australia and are used to working with 1/4" 3/8" 1/2" and 3/4" parts
and i think 15mm is 1/2, 20mm is 3/4 and 10mm is 3/8. but im not sure.
can anybody help me out with this?
and now my major question: what size input/output threads does this have?
http://www.ebay.com.au/itm/S3R-06-2-Pos ... 014wt_1141

thanks again

you people help me soooooooo much

Gun Freak · Sun Jul 31, 2011 9:02 am

8.5mm threads on that valve. Different than 1/8" though.

jmez1996 · Sun Jul 31, 2011 9:23 am

is there something at equates to 8.5mm threads though?

Gun Freak · Sun Jul 31, 2011 9:28 am

Yeh, 8.5mm threads :tongue3: 1/8" npt is probably the closest but I don't think they are compatible...

jmez1996 · Sun Jul 31, 2011 9:29 am

oh true

hmmmm well i need a 1/4 3 way valve for under $20 so ill keep looking

saefroch · Sun Jul 31, 2011 11:07 am

You may be able to find threads that are close and fudge it with a lot of teflon tape or epoxy, but it's best to connect threaded fittings how they were designed :p.

Zeus · Sun Jul 31, 2011 7:48 pm

Well if you want semi auto QEV operation, then this valve should do, if you can live with using a 1/4 to 1/2 bushing/nipple/coupling then this will do fine.

I'm in Australia too, so I know how difficult getting some fittings is.

Pneumaticology · Mon Aug 01, 2011 1:37 am

http://en.wikipedia.org/wiki/National_pipe_thread

jmez1996 · Mon Aug 01, 2011 6:31 am

hmmmm zues that could work. are you sure the 15mm/16mm slide valve is 1/2?
if so that could work. but i dont want to get something with a different thread because i probably cant get the adapters.

jmez1996 · Mon Aug 01, 2011 6:43 am

i measured the outside diameter of a 1/2 thread and its closer to 21-22mm
there is also this: http://cgi.ebay.com/1-2-1-2-Pneumatic-F ... 3a67bff163

however 12.7mm is even further away D:

Zeus · Mon Aug 01, 2011 7:33 pm

Those listings are bull, 1/2 inch NPT/BSP should be 12.7mm, but NPT fittings are way off.

Best bet is to ask the seller if the product is NPT/BSP compatible.

Technician1002 · Mon Aug 01, 2011 7:36 pm

NPT fittings are based on the Nominal ID of the pipe. As such they are typically 1/8th inch larger at the threads.

saefroch · Mon Aug 01, 2011 9:24 pm

Technician1002 wrote:NPT fittings are based on the Nominal ID of the pipe.

Uhhhhhh what??? A 3/8" NPT pipe has an ID of ~.5"