Can't comment on durability as I've only used it on one project so far. They seem to be well built, there are no burrs on the instrument, the case is good too. They made very good cuts for my first project with them. It is difficult to take the instrument out of the case at first, you must be careful because you can easily cut yourself when removing the instruments for the first time. I made a start for the case because it initially holds the tools so tightly that they are difficult to safely remove.