Help me identify this fitting thread

[Stigma]

My measurements (these are not perfect, just as good as I could get them with my availiable tools):

Diameter (outside of threads): ca 17mm
Distance between threads: ca 1.4mm
Not cone shaped as far as I can detect.

From my own research (I'm not good with piping) I suspect it might be a 3/8BSP or socalled British Standard.
Source: http://en.wikipedia.org/wiki/British...rd_pipe_thread

Is this the same as a G3/8?
In other words, can I use this for example in the same thread?:
http://www.frozencpu.com/products/71...01&id=C5xqMKZJ

-Stigma