The invention is directed to a surgical instrument comprising an elongate tube extending along an axis including a camming rod and an actuation mechanism operably connected to the camming rod, the camming rod having a camming pin and a camming projection a first jaw spine having a first cam slot, a first interior camming surface, and a first exterior camming surface and a second jaw spine having a second cam slot, a second interior camming surface, and a second exterior camming surface, the second jaw spine pivotally connected to the first jaw spine at a common pivot pin operably connected to the elongate tube to open and close the jaw spines in response to movement of the actuation mechanism. The camming pin rides along the first and second interior camming surfaces and operates to close the jaw spines when the camming rod is moved proximally. When the camming rod moves distally, the camming projection rides on the first and second exterior camming surfaces formed on the proximal sides of the respective first and second jaw spines and operates to open the jaw spines. A feature of the invention is one camming surface on each jaw spine can facilitate closing the jaw spines while the other camming surface on each jaw spine can facilitate opening the jaw spines. These two camming surfaces on each jaw spine can be widely separated. The jaw spines can be formed of a metallic material and are overmolded with an atraumatic plastic material. By overmolding the plastic onto the metal spine, an atraumatic outer surface can be formed of the plastic material along with a high degree of detail.
