DIN ISO 228 T1 is the only standard I know for metal (steel) pipe threads. This is also what i normally use in the plant; Some examples: Nominal pipe ID Thread as per ISO 228 approx ID of a US pipe sched.40 DN15 G1/2 16 mm DN20 G3/4 21 DN25 G1 27 DN40 G1 1/2 42 DN50 G2 52.5 Obviously this standard was "retrofitted" from the old BPT standard. The pipes are made to fit the old threads but have nominal metric ID. I know of other standards for plastic pipes, and tubing which are straight metric but I am not aware of a replacement to ISO 228 T1. A. -----Original Message----- From: kilopascal [mailto:[EMAIL PROTECTED]] Sent: Tuesday 06 March 2001 23:58 To: U.S. Metric Association Subject: [USMA:11485] NPT vs. PG 2001-03-06 Recently while doing some spring cleaning around my office, I came across a technical data sheet from a company called Panel Components. You may visit their website at http://www.panelcomponents.com. Of interest was the catalogue on Strain Reliefs; Data Sheet 148, 4/1999. Note the following from page 2: NPT and PG thread types Compared Interpower(TM) strain reliefs are available in two different types of mounting threads: NPT and PG. NPT (National Pipe Thread) is the American standard. PG (Panzer Gewinde) is an European standard. PG threads are sometimes referred to as metric threading; however, these threads are not truly metric. There is a metric system of threading that is slowly replacing PG threads, but very few people have actually started using metric threads at this time. Seeing that this catalogue is two years old, I wonder how far this true metric thread series has advanced. Has anybody heard of it? If you have, please post it here. BTW, for those who don't know German, Panzer Gewinde means armoured thread. John Keiner ist hoffnungsloser versklavt als derjenige, der irrtümlich glaubt frei zu sein. There are none more hopelessly enslaved then those who falsely believe they re free! Johann Wolfgang von Goethe (1749-1832)
