Abstract: A fastening member includes a screw thread formed therein. A portion including a crest portion of the screw thread is formed of a first alloy material and includes: a thick portion where the portion is maximized in thickness in a circumferential direction; and a thin portion where the portion is minimized in thickness in the circumferential direction. A portion including a root of the screw thread is formed of a second alloy material having a tensile strength higher than that of the first alloy material.

Abstract: It is an object to provide a locking bolt, which is capable of tightly fixing a member or the like at an extremely high degree of firmness without being loosened even when vibrations are repeatedly applied thereto, and is manufactured in an extremely facilitated manner. The locking bolt includes: a shank section (1) threaded on an outer circumference thereof; and a head section (2) provided at one end of the shank section (1). The head section (2) includes: a main body portion (201) having a hexagonal cross-sectional shape; and a cylindrical skirt portion (202) provided continuously with the main body portion (201) and formed so as to be spaced radially outward from the main body portion (201) in an expanding manner along a concave surface using a catenary curve surface.

Abstract: A thread forming screw having a minimum surface hardness of HRC 56. The screw can form threads in a workpiece having a surface hardness which exceeds HRC 23. A method of surface hardening a screw includes carbon enriching the screw to at least a 0.48 carbon level, and then quenching the screw. Then, the screw is tempered such that the surface hardness does not exceed the core hardness by more than 3 Rockwell C points, and both the surface and core are at a Rockwell C33-C39 hardness. Subsequently, the point is induction hardened, and the screw is quenched again. The screw is again tempered such that the lead threads and the first 3-4 full threads are at a Rockwell C56 minimum hardness, preferably to a depth of at least 0.008 inches, and the core of the fastener is at Rockwell C33-C39 hardness. Finally, a finish is applied.

Abstract: Reduced material content fasteners are provided that have a reduced material content portion between working ends allowing the fastener to have less weight with equal or better break and torque strengths. Systems and methods are provided for manufacturing reduced material content fasteners that provide for cold working the initial material to reduce the material while work hardening the remaining material. The cold working is provided by rolls and/or dies.

Abstract: A fastening element has a core zone (14) formed of a relatively hard carbon steel, a skin zone (17) located outwardly of the core zone (14) and formed of a first low-carbon austenitic steel alloyed with a first alloy metal, and an intermediate zone (15a, 15b) provided between the core zone (14) and the skin zone (17) and formed of a second low-carbon steel having a smaller hardness than the steel the core zone (14) is formed of.

Abstract: A hybrid fastening system comprising a female fastener component, i.e., swage collar, fabricated from a titanium or titanium-alloy material, preferably Ti-3Al-2.5V, and a mating titanium or titanium-alloy material male fastener component, i.e., threaded pin, each preferably pre-coated with an organic coating material comprising an organic, phenolic resin. The threaded pin component is installed through two or more structural components to be joined. The swage collar component is then deformed or swaged onto the threads of the pre-coated threaded pin component to achieve the same, if not improved, fastener/joint performance characteristics of existing lockbolt systems using aluminum-alloy material swage collar components.

Abstract: A hybrid fastening system comprising a female fastener component, i.e., swage collar, fabricated from a titanium or titanium-alloy material, preferably Ti-3A1-2.5V, and a mating titanium or titanium-alloy material male fastener component, i.e., threaded pin, each preferably pre-coated with an organic coating material comprising an organic, phenolic resin. The threaded pin component is installed through two or more structural components to be joined. The swage collar component is then deformed or swaged onto the threads of the pre-coated threaded pin component to achieve the same, if not improved, fastener/joint performance characteristics of existing lockbolt systems using aluminum-alloy material swage collar components.

Abstract: A high strength bold superior in delayed fracture resistant property has a bolt tensile strength of 1200 N/mm2. A high strength bolt comprised of a head portion and shaft portion formed by a steel material, wherein the relation between a bolt tensile strength TS (N/mm2) and tempering temperature T (° C.) satisfies the following expression (1), the relation between the bolt tensile strength TS (N/mm2) and the carbon equivalent Ceq (%) calculated from the chemical composition of the steel material used for the high strength bolt satisfies the following expression (2), and the tensile strength of the bolt is refined to a range of 1200 N/mm2 to 1600 N/mm2 by quenching and tempering: TS?1.1T+850??(1) TS?550Ceq+1000??(2) where, C eq = C + ( Mn / 6 ) + ( Si / 24 ) + ( Ni / 40 ) + ( Cr / 5 ) + ( Mo / 4 ) + ( V / 14 ) .

Abstract: A method of making a UHMWPE body combined with a bolt, a cap screw, a reinforcing member uses a compression molding machine equipped with a male and female mold set. Particulate UHMWPE dispensed into the cavity of the female mold surrounds the head of the bolt and screw and reinforcing member. Pressure and heat applied to the particulate UHMWPE molecularly bonds the UHMWPE to the bolt, screw, and reinforcing member.

Abstract: A threaded fastener lighter in weight and easier to produce is made by the moderate temperature-forging, from a raw magnesium material that contains microcrystals whose diameter is about 100 &mgr;m or less. The raw material may be pure magnesium of industrial grade in one case, and alternatively be any magnesium alloy or such a composition as comprising as its matrix the alloy or pure magnesium, in the other cases. The raw material has a superplastic property and a fine-granulated metallographic internal texture, and when making the fastener, will be heated to 250-400° C. at which superplasticity takes place to facilitate the forging to form the fastener. A method proposed in the invention to make the fastener is thus such that the number of necessary processing steps is reduced and manufacture cost is lowered.

Abstract: A method for heat treating a metal article such as a fastener comprising the step of case hardening the fastener in a gas carborizing atmosphere at a temperature of about 1700° F. or in a carbonitriding atmosphere at a temperature of about 1550° F., and quenching the fastener in water or oil and tempering the fastener at a minimum temperature of 770° F. for approximately one hour.

Abstract: A self-drilling/self-tapping fastener which is suitable for attaching a sprinkler system to a metal supporting structure has a driving head and an integral shank with a threaded portion. Process-hardening and threading of the shank harden the shank to a degree of hardness that retains sufficient ductility for resisting vibration loads. The drill tip at the end of the shank and the lead threads adjacent the drill tip are locally hardened to a relatively high degree of hardness for drilling and tapping the metal support members. A graduated transition zone separates the high-hardness zone from the lower-hardness zone, which allows for a single fastener to exhibit two distinctly different material properties in one fastener. The fastener through this dual process also exhibits two distinct load-carrying capabilities.

Abstract: A threaded fastener and a method by which the fastener exhibits sufficiently enhanced fatigue strength so as to be suitable for use in gas compressors and turbines operating at relatively high service temperatures. The method entails a selective heat treatment to achieve a dramatic improvement in fatigue properties while not interfering with other required properties for the fastener. The heat treatment process preferentially develops a case-hardened region in those threads nearest a transition region between the threads and an unthreaded portion of the fastener. In contrast, the unthreaded portion and the threads furthest from the transition region need not be case-hardened. The hardening pattern in the threads yields a martensitic steel fastener that exhibits fatigue properties which are dramatically superior to otherwise identical fasteners.