its a plastic i guess, shore d hardness was like 119 i think...machines well, and somewhere i read it glues fine....was thinking about getting some off ebay.
Also, it's a long ways from being as hard as phenolic. It's like a harder version of ABS, but it's still more like the thermoplastic that it is, rather than a thermoset like phenolic is.
The white color PPO looks translucent like Delrin.
One of the highlighted points about PPO was it does not bond well.
Just might not be a good property for no mechanical restraint. ..