Z axis speed?

Is 8.5mm/s (510 mm/m) the max Z speed for all-thread or leadscrew? Seems like I read a post somewhere that listed a revised max for leadscrew, but I can’t for the life of me come up with it. Thx

8.4 is for the allthread, the newest firmware allows for 30mm/s for the T8.

Muchos gracias! Obviously won’t be plunge cutting anywhere near that rate, but didn’t want to rapid too fast and lose steps.