Mechanical limit switches - acceptable practice?

[Al Skierkiewicz]

So far everyone is correct as to the rules for 2014 (Mark, Jon and Philso). I would like to add that is pretty easy to design the limit switch mounting such that it will not be damaged by over-travel in the mechanism it is designed to limit. Rather than hitting the switch lever head on, just design it so that the lever "follows" the mechanism that is being sensed. By doing that, no stress is placed on the switch or the operating lever.