Abstract: An anti-loose screw (20) includes a shank (24) having an external thread (28) with a thread angle of 63° to 68° between two flanks (34, 36) extending between a crest (30) and a root (32). A first angle (A) between one of the flanks (34, 36) and an axis (Y) extending perpendicularly to a longitudinal axis (X) of the shank (24) and passing through the crest (30) is in a range between 34° and 40°. A second angle (B) between the other flanks (34, 36) and the axis (Y) is in a range between 25° and 29°. The anti-loose screw (20) can engage with an object (40) having an internal thread (42) with a thread angle of 60° to provide an interference fit and can be formed by two dies (120, 140) each including a thread forming configuration (128, 148) having correspondingly formed ridges (130, 150) and valleys (136, 156).

Abstract: In various embodiments, a tapered thread roll, a set of tapered thread rolls, a thread rolling tool, and a thread rolling method are provided for rolling angled or tapered threads onto a workpiece to create a threaded workpiece. In at least one embodiment, the threaded workpiece may comprise a polished rod or a polished rod precursor as specified by the American Petroleum Institute for use in an oil-field sucker-type pump, for example.

Abstract: Machining techniques and machining apparatus are provided for treating workpieces in an efficient and reliable manner. The machining techniques and machining apparatus employ multiple thread whirling heads associated with a single machining assembly, such that each of the thread whirling heads is able to act on a workpiece during a single, uninterrupted machining process. Screw threads may be formed that include first and second thread profiles and an intermediate transition region. The machining apparatus generally includes a processor that is programmed to control operation of the multiple thread whirling heads in a sequential manner.

Abstract: A method and apparatus for manufacturing a bolt capable of mass-producing a multiple screw bolt such as a so-called double screw bolt at a low unit price, and a thread rolling die for use therein. The apparatus for manufacturing a bolt comprises a pair of thread rolling dies (1) which are arranged opposite to each other at a predetermined interval, and a bolt supporting unit (2) which supports a cylindrical bolt material (3) in a predetermined position. The thread rolling dies (1) are provided with a transfer pattern (4) having a coarse thread portion (5) which is part of a coarse thread formed by developing a coarse screw, and projections (6) which are part of a fine thread (6a) formed by developing a fine screw as shown by an imaginary line (6a), the fine thread (6a) being formed cyclically on a root portion (5a) of the coarse thread according to a phase shift between the fine thread and the coarse thread.

Abstract: A threaded fastener comprises a first, primary thread lead, and a pair of second, auxiliary thread leads alternatively interposed between successive threads of the first, primary thread lead, except within the vicinity of the tip portion of the fastener so as to define space for accommodating debris generated during the self-tapping of the fastener into a workpiece. The fastener also comprises lobe members formed upon the primary thread lead so as to predeterminedly affect torque insertion and pull-out resistance values.

Abstract: A new and improved thread rolling die, for forming a new and improved threaded fastener, comprises a plurality of first, primary thread rolling die threads, and a plurality of sets of second, auxiliary thread rolling die threads alternatively interposed between successive threads of the first, primary thread rolling die threads, so as to render the manufacturing process more cost effective by reducing the the number of revolutions, through which a blank member must be rotated in order to complete the formation of the thread leads upon the blank member, to be accordingly reduced which, in turn, permits the axial length of the thread rolling dies, and the thread rolling machines, to be reduced in size.

Abstract: A new and improved thread rolling die for forming a new and improved threaded fastener, and a new and improved method or technique of manufacturing the new and improved threaded fastener, is disclosed wherein the new and improved threaded fastener comprises a first, primary thread lead, and a pair of second, auxiliary thread leads alternatively interposed between successive threads of the first, primary thread lead. As a result of the provision of the pair of second, auxiliary thread leads being interposed between successive ones of the threads of the first, primary thread lead, not only is additional axial reinforcement provided for the threaded fastener, but more importantly, the lateral or transverse distance through which the material comprising the blank member must be displaced or moved in order to form the successive threads of the first, primary thread lead is substantially reduced.