A lot of talk in this thread about those that have kissed in a tight turn.
If you have a short box and a non-sliding hitch, do your homework. Go to a wide open FLAT parking lot, and find out what where that contact point is, and burn that into your mind. I think you'll find that point is LESS than you think it is.
I've said this before, but it's worth reiterating. If you measure the distance from your back glass to the pivot point (center of ball, or fifth wheel) and that distance is LESS than 1/2 the width of your trailer, you CANNOT make it to 90degrees without crashing. For Montana owners, 1/2 of the trailer width should be 96"/2 = 48", but measure yours to be sure. Any dimension from the back glass to the pivot of less than 48" is a potential issue with crashing when turning. Remember those front cap corners that give you relief? They do nothing at a certain point, and you can still hit. I think that there's a misconception out there that knocked off corners on the cab will keep you from hitting. That just is not the case.
At the end of the day, be aware, and know what those limits are, and if you don't have a slider, you MUST stay inside those limits...
Here is a good video that explains all of this, and extended pin boxs: