A one-piece handle assembly and a method of assembling the one-piece handle assembly. The one-piece handle assembly includes an outer tube connected to a fixed jaw and an inner tube connected to a moveable jaw. The inner tube is installed within the outer tube. The surgical instrument assembly further includes a handle body overmolded onto the outer tube and a handle grip connected to the handle body. The handle grip controls movement of the moveable jaw along an axis about defiend through the outer tube. The one-piece handle assembly further includes a knife plunger for controlling activation of a knife rod assembly. The one-piece handle assembly is void of any welds, adhesives, or fasteners to complete the final assembly of the one-piece handle assembly.
