A hollow screw and related process of making is provided, wherein the hollow screw is formed from a generally circular corrosion resistant stainless steel disk cut from flat roll stock. The hollow screw includes a head and an elongated and hollow shaft having a wall thickness between about 0.2 to about 0.7 millimeters extending therefrom and defining a shank portion and a threaded portion having a plurality of threads thereon with a rotational drive mechanism configured to facilitate tightening via the threads. The process involves annealing to soften the stamped hollow screw, followed by thread rolling, and then age hardening the hollow screw. As such, the resultant hollow screw is relatively lightweight, about 50% the mass of a solid core screw made from the same material, with a sufficient thread strength to meet most aerospace applications and contributes to important aircraft fuel economy.

The production method according to the invention for creating a thread in an elongated semi-finished product comprises the following steps: shaping, especially lengthwise rolling, of at least two lengthwise grooves into a blank and lengthwise rolling of a thread into the areas circumferentially delimited by the grooves. The distance from the beds of the grooves to the axis of the blank is smaller than the distance from the root of the thread to the axis.

The production method according to the invention for creating a thread in an elongated semi-finished product comprises the following steps: shaping, especially lengthwise rolling, of at least two lengthwise grooves into a blank and lengthwise rolling of a thread into the areas circumferentially delimited by the grooves. The distance from the beds of the grooves to the axis of the blank is smaller than the distance from the root of the thread to the axis.

The die forming process includes first passing a circular coarse thread cutter over the forming surface of the die at an angle away from parallel to a side edge matching a pitch for coarse threads to be formed by the die. In a first cutting step, the coarse thread cutter forms upper portions of crests in the forming surface of the die. In a further step, a fine thread cutter is then utilized to cut portions of the root of the dual threaded die, leaving a bridge within the root. The fine thread cutter is angled relative to the crests formed in the first step. The fine thread cutter cuts at a variable depth as the fine thread cutter advances along the root between the crests to form two flanks on sides of the bridge within the root.

A method for forming a stop flange on a self-tapping screw includes locating a shank of a self-tapping screw between two threading dies, fixing one of the two threading dies and moving the other one of the two threading dies to work the shank, the external thread forming section of each of the threading dies performing threading to form an external thread on the shank, inserting the insert and the recessed corner of each of the threading dies into a top of the external thread to form a groove in the shank, and the insert of each of the threading dies gradually squeezing downward an extruded portion that is formed during formation of the groove to form a stop flange on the shank. Thus, the shank is integrally formed with the stop flange, to stop an excessive movement of the external thread.

A formed body of Cu—Al—Mn-based shape-memory alloy may include a screw portion, wherein the screw portion is a form-rolled portion. A method for producing a formed body of Cu—Al—Mn-based shape-memory alloy may involve forming a screw portion having superelasticity by plastically working at least a portion of a material for the formed body with form-rolling in a state that a crystal structure is an A2-type structure and then, subjecting heat-treatment so as to convert the A2-type crystal structure into an L.sub.21-type crystal structure. The screw portion can be formed with good working property, and has excellent fatigue resistance and breaking resistance.

A formed body of Cu—Al—Mn-based shape-memory alloy may include a screw portion, wherein the screw portion is a form-rolled portion. A method for producing a formed body of Cu—Al—Mn-based shape-memory alloy may involve forming a screw portion having superelasticity by plastically working at least a portion of a material for the formed body with form-rolling in a state that a crystal structure is an A2-type structure and then, subjecting heat-treatment so as to convert the A2-type crystal structure into an L.sub.21-type crystal structure. The screw portion can be formed with good working property, and has excellent fatigue resistance and breaking resistance.

The present invention relates generally to a container that may be sealed and reclosed with a threaded closure. More specifically, the present invention relates to methods of manufacturing a metallic container having an opening with inwardly facing threads that are formed after a threaded closure is inserted at least partially into the opening. The container opening may be selectively sealed and reclosed with the threaded closure which releasably engages the container threads.

The invention relates to a wood screw having a screw head having a drive configuration, a screw shank which emanates from the screw head and which at least in portions is provided with a thread, and a drilling tip which adjoins the thread, wherein the drilling tip is configured without a thread, wherein the drilling tip has two longitudinal cutters which continue up to a terminal point of the drilling tip and which run so as to be curved in relation to a central longitudinal axis of the screw, and wherein a circumference of the drilling tip between the two longitudinal cutters does not have any further cutters.

The invention relates to a wood screw having a screw head having a drive configuration, a screw shank which emanates from the screw head and which at least in portions is provided with a thread, and a drilling tip which adjoins the thread, wherein the drilling tip is configured without a thread, wherein the drilling tip has two longitudinal cutters which continue up to a terminal point of the drilling tip and which run so as to be curved in relation to a central longitudinal axis of the screw, and wherein a circumference of the drilling tip between the two longitudinal cutters does not have any further cutters.