For internal doors.
I tapped on my son's bedroom door the other day. The door wouldn't open. Nor when he tried. So I got a screwdriver and took the handle off. The little square hole in the latch for the drive shaft would go round and round quite happily. A little lateral thinking later and I got him to drive the pins out of the hinges, then levered the door across a bit, gave it a smart tap and the hinges popped off so at least he could get in and out. But it's kind of worrying that the doors might decide to sulk like this - especially as the latch on that one is only a few months old, as the old one wore off.
The reason it failed seems to be a dodgy casting:
The real reason I'm writing this is - can anyone recommend a decent make so I can replace them as they die with decent ones? They normally fail gradually, but they still fail to often for my liking.
Ta
Andy