Type 'G' Thread? 1

[snubengr]

Does anyone have any information on this thread standard? Specifically I have seen it referenced as G1/2A and G2-1/2. Are these perhaps a metric version of a tapered thread like NPT?

Thanks in advance for any help/advice.

 

[boo1]

MOST METRIC COUNTRIES IN EUROPE AND ASIA USE THE BRITISH BASED INCH SYSTEM (ISO) FOR MEASURING PIPE AND TUBING THREADS. THREADS EQUIVALENT TO BSPP/BSPF (BRITISH STANDARD PIPE - PARALLEL) ARE DESIGNATED IN GERMANY AS: G 1/4. THE REFERENCE STANDARDS FOR ISO R228 PARALLEL PIPE THREAD ARE DESIGNATED AS: GERMANY - DIN 259