A dead blow hammer a stepper motor and a temper

Long story short is that I killed a stepper motor . No biggie it gave me an excuse to ditch the chinese crap and put on something decent .
Now I'm curious about the impact resistant of a stepper motor , I gave the sucker a good whack but nothing that I would have considered as extreme ( maybe it was a bit). I would have thought that a guy could be pretty rough with a stepper motor but obviously not .
Are there certain parameters regarding impact and vibration that these motors have to stay within







.