Abstract: A novel collet and chuck are disclosed for applying high levels of torque to an article having substantially circular cross-sections about a common axis and sloping sides, such that it cannot be readily gripped by conventional chucks without marring the exterior surface of the article. A collet is provided which is reinforced against torsional distortion and which provides a rubber interior surface conforming to the article. Torque levels as high as 1700 inch-pounds may be applied to such articles, such as projectile shells, in accordance with the invention. Means are provided for rapidly releasing the article from the chuck after the torquing operation.

Abstract: A method and apparatus is disclosed for operating upon a workpiece having an internal cylindrical bore therethrough to form one or a plurality of circumferential grooves within the bore. The workpiece is held in a collet and a tool is inserted therethrough and supported for rotation at both ends. The tool has on its outer surface a row of cutting teeth for each groove to be made and has an exterior diameter including the teeth that is less than the internal diameter of the bore in the workpiece. With the tool rotated at a relatively high RPM in one direction and the workpiece rotated at a relatively low RPM in the opposite direction, the collet supporting the workpiece is moved laterally of the tool axis to contact each of the rows of cutting teeth against the internal wall of the workpiece. A single revolution of the workpiece is thus sufficient to form the entire cut. A specific arrangement of the teeth on the tool is also disclosed.