When I received the knife it felt and sounded like there was dirt/sand in the hinge so it was difficult to open and close. I considered returning it but decided instead to take it apart, clean it out and re-oil it. After the cleaning it worked significantly better. I have noticed that the locking mechanism isn't as secure as I would have hoped. When pressure is applied the blade tends to flex towards closing so be wary if using in any direction other than away from you.