Positioning grippers hold and accurately position workpieces for a variety of workholding, toolholding, and factory automation applications. Threaded self-aligning grippers have hex-shaped bodies with a threaded stud. Fully-threaded self-aligning grippers have cylindrical bodies that are externally threaded along their full length. Hex-head gripper screws have a threaded body with a gripper pad on the hex head. Tapped self-aligning grippers have cylindrical bodies that are internally threaded. Square gripper pads work with hard materials or workpieces with irregular surfaces. Round gripper and positioning inserts provide strong gripping force.