Abstract: A fastener which includes a threaded pin having a notched helical thread to receive a threaded collar which, after being set to a torque, is deformed to move material into some notches on the thread to form a lock to prevent unthreading. The notched thread can be formed by a three-section roll die, the first section of which forms the thread, the second of which notches the thread, and the third section of which smoothes the thread. The invention comprehends the die, the die forming method, the pin, the pin and collar, and a joint formed with the pin and collar.

Abstract: A fastener includes a threaded pin and an internally threaded collar. The threads can freely be run without impediment during tightening. After the fastener is tightened, a tool engages a shoulder on the collar and presses a deflector against the collar on the pin to deflect it so as to form a lock against loosening.

Abstract: A threaded fastener has a pin with a head, a cylindrical shank, a shoulder with reducing diameter, a radius at the least diameter of the shoulder whose region is work-hardened, and a threaded end, in that order. The thread extends into near-adjacency to the shoulder, and has no more than approximately one-half of a convolution of an incomplete thread at its end adjacent to the shoulder. A collar is threadable onto the thread. It has a counterbore no longer than the anticipated grip range plus approximately one-half of a thread pitch. The collar may be inherently torque-limited. The term "thread" also includes a peripheral groove.

Abstract: A fastener and a joint including the fastener, wherein the material in which the fastener is set is a composite. The fastener has a shank with an external helical rib that makes a slightly tighter than net to a moderate interference fit in a cylindrical wall of the hole. The rib has a form whose maximum radial protrusion is flat or convex, and which extends away from its maximum protrusion as a convex curve, devoid of sharp cutting edges. Voids between the convolutions of the rib are adequate to receive displaced material of the hole wall.

Abstract: A security fastener has a threaded body with tool engaging surfaces. It is surrounded by a freely rotatable spinner. When the fastener is tightened down the tool engaging surfaces are removed so there is nothing on the fastener to be engaged by a tool. The side of the fastener is shielded by the rotatable spinner.

Abstract: A threaded fastener has a pin with a head, a cylindrical shank, a shoulder with reducing diameter, a radius at the least diameter of the shoulder whose region is work-hardened, and a threaded end, in that order. The thread extends into near-adjacency to the shoulder, and has no more than approximately one-half of a convolution of an incomplete thread at its end adjacent to the shoulder. A collar is threadable onto the thread. It has a counterbore no longer than the anticipated grip range plus approximately one-half of a thread pitch. The collar may be inherently torque-limited. The term "thread" also includes a peripheral groove.

Abstract: A metallic balanced pin for a shear flow joint, and a fastener and joint including the pin. The pin has a head, a cylindrical shank and a reduced neck. The neck includes a peripheral groove, a helical thread being an example. The inherent strengths of the head and groove are substantially equal and only sufficient to resist axial tensile forces exerted by bending in a shear flow joint. The inherent strength of the shank section is sufficient to resist shear forces in the joint. Preferably the intersection of the neck and a transition section connected to the shank section is locally work-hardened to resist fatigue forces.

Abstract: A depth gage for indicating the depth of a hole through a workpiece which is to be attached to a nut-plate by a threaded fastener, comprises a rod with a cylindrical portion adapted to pass through the hole and abut the nut-plate so that a forward section of the rod enters within the threads of the nut-plate. A sleeve slidable on the rod in front of the workpiece can be slid to abut the front surface of the workpiece. Graduated markings on the rod indicate the depth of the hole.