Do the NX Routing Part Table (PTB) files support mixed units in a single PTB file?
Routing is supplied with two libraries named "Metric" and "English". The names of these libraries are just names - they could have been called "library1" and "library2". It was just a way to provide two libraries, and yes one includes metric parts and the other english parts, but there's no problem combining them.
There are however two limitations that should be considered:
1) The regular limitations of NX with mixed unit assemblies. And just like regular NX, you can add both metric and english unit parts to an assembly of either metric or english units.
2) The limitation of the stock ptb, specifically the ones that don't refer to part files. I.e., those that don't refer to actual NX part files like wiring, cable, and overstock. There is a DIA field in those ptb's and the DIA is interpreted in the units of the assembly where the stock is created.
So if the stock is in english units, but going to be used in a metric assembly, the DIA should be in metric units. And that holds for other numerical attributes, but is most evident with stock.
Notes and References
OS Version: 764SP1