Special ID thread. sp-400 "M" type thread 8TPI

HI. I am working on a prototype job and need some help. There are three pieces (Delrin) to the assembly-I think it comes together as a valve for wine barrels, some type of valve for wine. Anyway, the valve body calls for a "sp-400 "M" type thread 8 TPI". This is an ID thread. This drawing is poor, but it calls 3 dimensions in that area, 1.750 OD, 1.650 ?, and 1.550 ? The model is in .stp format and I cannot open this one-corrupt file.

I think this thd might be similar to a plastic gas can, or some other irregular thd with a unique application. I would appreciate any info. I am only making the part with the ID thd. Need threadform profile, minor dia, and maybe info for an od thd so I can make a gage.

I am so glad I signed up on this site-there are so many friendly, smart people who have helped me a number of times.

Thanks so much.


sp-400 "M" type thread 8 tpI---ID thread

Only information I could find is here:

Type M - Straight Swivel Fitting - External Thread

And here:

http://www.hammelmann.de/PDF_english...sting_guns.pdf

Also this:

Modified Buttress Thread

Commonly referred to as “M?style. The modified buttress thread was developed, with a 10 degree pressure angle, to offer more closure-to-bottle thread contact. Found here: http://www.kenplas.com/topic/glossary/plascap.aspx

Finally: bags or bottles with sp400 38mm threads material polypropylene coupling and Found here: http://www.who-sells-it.com/cy/colde...-fullsize.html And here: http://www.who-sells-it.com/cy/colde...read-caps.html