A bolt is provided that has high strength and excellent hydrogen embrittlement resistance characteristics. A bolt according to an embodiment of the present invention consists of, in mass %, C: 0.32 to 0.39%, Si: 0.15% or less, Mn: 0.40 to 0.65%, P: 0.020% or less, S: 0.020% or less, Cr: 0.85 to 1.25%, Al: 0.005 to 0.060%, Ti: 0.010 to 0.050%, B: 0.0010 to 0.0030%, N: 0.0015 to 0.0080%, 0: 0.0015% or less, Mo: 0 to 0.05%, V: 0 to 0.05%, Cu: 0 to 0.50%, Ni: 0 to 0.30%, and Nb: 0 to 0.05%, with the balance being Fe and impurities. The bolt satisfies Formula (1) and Formula (2), and has a tensile strength of 1000 to 1300 MPa and satisfies Formula (3).

4.910C+Si+2Mn+Cr+4Mo+5V6.1 (1)

Mn/Cr0.55 (2)

[dissolved Cr]/Cr0.70 (3)

A bolt is provided that has high strength and excellent hydrogen embrittlement resistance characteristics. A bolt according to an embodiment of the present invention consists of, in mass %, C: 0.32 to 0.39%, Si: 0.15% or less, Mn: 0.40 to 0.65%, P: 0.020% or less, S: 0.020% or less, Cr: 0.85 to 1.25%, Al: 0.005 to 0.060%, Ti: 0.010 to 0.050%, B: 0.0010 to 0.0030%, N: 0.0015 to 0.0080%, 0: 0.0015% or less, Mo: 0 to 0.05%, V: 0 to 0.05%, Cu: 0 to 0.50%, Ni: 0 to 0.30%, and Nb: 0 to 0.05%, with the balance being Fe and impurities. The bolt satisfies Formula (1) and Formula (2), and has a tensile strength of 1000 to 1300 MPa and satisfies Formula (3).

4.910C+Si+2Mn+Cr+4Mo+5V6.1 (1)

Mn/Cr0.55 (2)

[dissolved Cr]/Cr0.70 (3)

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.

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.

A coupling system for attaching a first part to a second part using a locator and expansion shear pin is disclosed. The first part has a first flange and may be a formed part, such as an intake manifold. The second part has a second flange and may be a component, such as a throttle body, for attachment to the first part. The component includes a fastener-passing bore having an inner diameter. The locator and expansion shear pin extends perpendicularly from the first flange. The pin includes an expansion wall extending beyond the surface of the flange. A fastener-receiving bore is formed concentrically in the pin relative to the wall. The wall is expandable from a first diameter to a second diameter. The first diameter is less than the inner diameter of the fastener-passing bore. The second diameter is at least equal to the inner diameter of the fastener-passing bore.

The specification discloses a fastener assembly (10) having a bolt stud or pin (13) with a threaded section (15) at one end, a nut member (11) threadable onto the threaded section (15), the fastener assembly (10) further including a cup shaped cover member (30) with a continuous wall structure having an internal surface defining an internal space (42), the continuous wall structure having an open mouth region (33) with a seal zone (35) and a continuous seal member (32), the internal surface (43, 44) of the cover member (30) having first snap-in formations (45) cooperating with second snap-in formations (48) on an outer surface region of the threaded nut member (11) to prevent disengagement of the cover member (30) from the nut member (11) and to press said continuous seal member (32), in use, against a sealing region around said nut member (11) to thereby prevent ingress of contaminants and corrosive materials into the internal space (42).

An electric connector comprises a wall surrounding a receptacle that receives a strand of an electric wire and having a threaded hole extending through the wall and opening into the receptacle, and a fastener bolt screwed into the threaded hole and clamping the electric wire. The fastener bolt includes a bolt part having a head section, a thread section and a shearing section connecting the head section and the thread section. The fastener bolt further includes a nut part screwed onto the thread section. The shearing section is adapted to break if a predetermined fastening torque is exceeded. The thread section is hollow and has a predetermined tensile breaking strength.

This invention provides a thumb screw connecting structure, including a thumb screw, a first stopper, and a second stopper, the first stopper and the second stopper are fixedly connected via the thumb screw; and a protruding fixing portion is disposed at the second stopper, an internal thread fitting the thumb screw is disposed inside the protruding fixing portion, and the protruding fixing portion is used to fix the thumb screw. The thumb screw connecting structure is convenient and efficient in use, the first stopper and the second stopper can be fixed without using a wrench or other tools, which is convenient as well as practical. This invention further provides a table and a chair, and the table and the chair are fixed by adopting the thumb screw connecting structures, which is convenient and practical when assembling and disassembling.

This invention provides a thumb screw connecting structure, including a thumb screw, a first stopper, and a second stopper, the first stopper and the second stopper are fixedly connected via the thumb screw; and a protruding fixing portion is disposed at the second stopper, an internal thread fitting the thumb screw is disposed inside the protruding fixing portion, and the protruding fixing portion is used to fix the thumb screw. The thumb screw connecting structure is convenient and efficient in use, the first stopper and the second stopper can be fixed without using a wrench or other tools, which is convenient as well as practical. This invention further provides a table and a chair, and the table and the chair are fixed by adopting the thumb screw connecting structures, which is convenient and practical when assembling and disassembling.

A high-strength bolt is provided that has high strength and excellent hydrogen embrittlement resistance characteristics. A bolt according to this invention has a chemical composition consisting of, in mass %, C: 0.22 to 0.40%, Si: 0.10 to 1.50%, Mn: 0.20 to less than 0.40%, P: 0.020% or less, S: 0.020% or less, Cr: 0.70 to 1.45%, Al: 0.005 to 0.060%, Ti: 0.010 to 0.045%, B: 0.0003 to 0.0040%, N: 0.0015 to 0.0080% and O: 0.0020% or less, with a balance being Fe and impurities, and satisfying Formula (1) and Formula (2), and with the high-strength bolt having a tensile strength of 1000 to 1300 MPa.

0.50C+Si/10+Mn/5+5Cr/220.85(1)

Si/Mn>1.0(2)

Where, a content (mass %) of a corresponding element is substituted for each symbol of an element in Formula (1) and Formula (2).