A threaded-shaft or fastener such as a headless bone screw, intramedullary support or the like, has a tool-receiving structure on the axial end of an externally threaded proximal end for application of torque directly to the fastener. A cannulated cap nut with internal threads complementary to the thread on the shaft can be jammed on the shaft in a tightening direction, allowing driving torque to be applied to the shaft through the cap nut for driving the fastener into a work material such as bone tissue. When the fastener has been driven to bring the cap nut up to the work material, torque is applied between tools in the fastener and cap nut, and then to the fastener alone, unjamming and advancing the fastener such that the proximal end of the fastener can be embedded in the bone tissue. The fastener is advantageously a headless bone compression screw.
