Abstract: A thread rolling die and a method of thread rolling is disclosed for producing the annular rib on a threaded fastener suitable for retaining washers, clips or the like. The ends of the threads adjacent to such rib blend to the root diameter of the thread. The annular rib is produced by axially displacing workpiece material from the adjacent end of the thread. The die for rolling the thread is formed with thread forming grooves which extend to a base line spaced from the parallel to the lateral side of the die. At the base line the thread forming grooves fade to zero depth. Positioned between the base line and the lateral side of the die is a rib of increasing width which functions to displace material axially into the required rib.

Abstract: An improved tool in the form of a tooth forming rack for cold working a cylindrical workpiece to form teeth thereon to produce, for example, a toothed gear is provided. The rack comprises a plurality of releasable inserts mounted on a tool holder. The inserts are of the throw-away type which enables replacement of only that portion of the rack that is worn or broken, thus extending the ueful life of the entire rack. In a first embodiment the inserts are releasably attached to the tool holder by threaded capscrews. In an alternate embodiment a milled slot within the inserts permits retention by means of tapered retainers attached to the tool holder by threaded capscrews.

Abstract: Apparatus and a method for splining annular thin wall power transmission members in a manner that provides precise spline formation and accurately maintains the roundness of the splined members. A toothed pinion type mandrel of the apparatus mounts a power transmission member to be splined between a pair of cooperable dies of the apparatus. Each die has at least one first tooth group and a second tooth group, and teeth of each tooth group are spaced therealong with the teeth of the first group spaced farther from each other than the teeth of the second group. Driving of the dies relative to each other and the power transmission member mounted on the mandrel initially engages the farther spaced teeth with the mounted transmission member so as to cooperate in a meshing relationship with the toothed mandrel with the power transmission member therebetween to form a first set of splines.

Abstract: A method and machine for splining a power transmission member by rolling are disclosed as well as the resultant splined member. An externally toothed pinion-type mandrel of the machine is rotatably mounted between a pair of elongated dies. An unsplined member is supported by the mandrel so that sliding movement of the elongated dies from an end-to-end relationship to an overlapping relationship meshes teeth on the dies and the teeth on the mandrel with a thin-walled annular sleeve portion of the member therebetween. The meshing of the die and mandrel teeth deforms the sleeve portion of the member radially to form the splines and also rotates the mandrel to complete the spline forming operation about the total circumference of the member. The mandrel may be removably mounted in a manner that permits a pair of the members to be simultaneously splined by a single stroke of the elongated dies.

Abstract: A method and apparatus for assembling a screw and an axially compressible washer and rolling threads on the screw blank in a single operation that results in a shank configuration immediately beneath the head of the screw that allows complete compression of the washer. The method involves assembling a washer on the blank and retaining it thereon while the washer and screw assembly are subjected to swaging forces from opposing reciprocating thread rolling dies. The washer is retained on the blank in such a manner as to allow the thread rolling dies to swage an upper section of the blank and thereafter move the washer upwardly directly adjacent the head in a single thread rolling pass.

Abstract: A thread-rolling method as well as thread-rolling dies and method for manufacturing the dies. The shank on which the thread is rolled has a tapered free end region, and the dies which are used for rolling the thread are initially made up of a pair of individual sections having flat and inclined die faces with these sections subsequently joined to each other to form the complete die. The threads may be of lobular configuration, and during the rolling of the thread itself the lobes are simultaneously formed. The lobes for the threads are achieved directly from the thread-rolling dies by pressing across the ridges thereof tools which form in the ridges indentations having a predetermined pattern of distribution which will achieve the required distribution of the lobes on the thread which is rolled.

Abstract: A vibration-resistant, thread-forming screw. The screw has an elongated shank made of a solid, one-piece body and provided with an interior core portion which, in any plane normal to the shank axis, has a circular configuration. Integral with and projecting radially from this core portion are a plurality of lobes uniformly distributed circumferentially about the shank axis and extending along spirals which progress angularly about the shank axis in a direction opposite to the thread. Each lobe has, in the direction in which the screw is turned into a body, an elongated leading leg which progresses gradually away from the shank axis in the latter direction of turning and a relatively short trailing leg which returns abruptly toward the shank axis before joining the leading leg of the next lobe. A specially shaped die for forming the screw.