This is a link to all the paperwork for the Powermax 900
https://www.hypertherm.com/Download?fileId=HYP104432&zip=False
Above is a link to the PowerMax 900 operations manual.
Page 53-54
Hypertherm keeps a pretty decent library of all their current and Legacy equipment.
Half inch does fall off the chart, maybe 18-19 IPM @ 55amps