Provided are a bolt that exhibits excellent delayed fracture resistance at a high strength level of from 1,200 MPa to less than 1,600 MPa in tensile strength, where the possibility of delayed fracture is generally quite high, and a steel material for a bolt to be used as the material for such a bolt. The bolt has a composition satisfying Formulae (1) and (2), and a tensile strength of from 1,200 MPa to less than 1,600 MPa. In Formula (1) and Formula (2), Mo and V represent the contents (% by mass) of Mo and V contained in the steel for a bolt, respectively.

0.48≤Mo/1.4+V<1.10   (1)

0.8<Mo/V<3.0   (2)

Provided are a bolt that exhibits excellent delayed fracture resistance at a high strength level of from 1,200 MPa to less than 1,600 MPa in tensile strength, where the possibility of delayed fracture is generally quite high, and a steel material for a bolt to be used as the material for such a bolt. The bolt has a composition satisfying Formulae (1) and (2), and a tensile strength of from 1,200 MPa to less than 1,600 MPa. In Formula (1) and Formula (2), Mo and V represent the contents (% by mass) of Mo and V contained in the steel for a bolt, respectively.

0.48≤Mo/1.4+V<1.10   (1)

0.8<Mo/V<3.0   (2)

An electronic apparatus includes a bottom cover, a main board provided with a stud, a screw, a washer, and a sponge. The screw has a head portion having a diameter larger than that of an attachment hole, a male screw portion configured to be screwed into a first female screw portion, and a columnar portion having a diameter smaller than a root diameter of the male screw portion. The washer has a flange portion having a diameter larger than that of the attachment hole, a cylindrical portion having a diameter smaller than that of the attachment hole, and a second female screw portion which the male screw portion is screwable into and passable through. The head portion abuts on the bottom cover to fix the bottom cover by the male screw portion. The flange portion is between the stud and the bottom cover.

An electronic apparatus includes a bottom cover, a main board provided with a stud, a screw, a washer, and a sponge. The screw has a head portion having a diameter larger than that of an attachment hole, a male screw portion configured to be screwed into a first female screw portion, and a columnar portion having a diameter smaller than a root diameter of the male screw portion. The washer has a flange portion having a diameter larger than that of the attachment hole, a cylindrical portion having a diameter smaller than that of the attachment hole, and a second female screw portion which the male screw portion is screwable into and passable through. The head portion abuts on the bottom cover to fix the bottom cover by the male screw portion. The flange portion is between the stud and the bottom cover.

A centering fastener, a method for manufacturing the centering fastener, a method for using the centering fastener and a wind turbine are provided. The centering fastener includes a connecting body, a buffer lining and a centering member, the connecting body is a columnar body and includes a connecting portion and a non-threaded portion; the buffer lining has a cylindrical shape and covers at least part of the non-threaded portion; the centering member covers an outer surface of the buffer lining, and, at least at a portion corresponding to the buffer lining, the non-threaded portion is separated from the centering member.

A centering fastener, a method for manufacturing the centering fastener, a method for using the centering fastener and a wind turbine are provided. The centering fastener includes a connecting body, a buffer lining and a centering member, the connecting body is a columnar body and includes a connecting portion and a non-threaded portion; the buffer lining has a cylindrical shape and covers at least part of the non-threaded portion; the centering member covers an outer surface of the buffer lining, and, at least at a portion corresponding to the buffer lining, the non-threaded portion is separated from the centering member.

Laterally adjustable hooks may be used to join two or more substantially planar parts, such as two halves of a splitboard. In an embodiment, a laterally adjustable hook comprises a unitary body having a top surface, a bottom surface, a main portion and a nose portion, with the main portion comprising at least one oblong, beveled slot and the nose portion extending from an end of the main portion. A screw or wedge nut may be used to apply pressure to edges of the oblong, beveled slot, and a pair of set screws may contact and laterally secure the wedge nut.

A fastener system attaches a connector or other upper member to a lower structural member such as a post or beam. The fastener systems consists of a fastener having an extending shank that is driven into a lower structural member and the fastener is received by a washer that also has an extending tube, and the extending tube of the washer is received by the connector or upper member.

A fastener system attaches a connector or other upper member to a lower structural member such as a post or beam. The fastener systems consists of a fastener having an extending shank that is driven into a lower structural member and the fastener is received by a washer that also has an extending tube, and the extending tube of the washer is received by the connector or upper member.

Threaded parts such as bolts are rust-proofed by using a treatment liquid including a binder resin containing silica and at least one of a modified epoxy resin obtained by graft polymerization using a carboxylic acid-containing acrylic polymer as a side chain and a modified acrylic resin obtained by graft polymerization using a carboxylic acid-containing acrylic polymer as a side chain. By using this treatment liquid, coating treatment can be carried out at one time without need to use an organic solvent. There is an advantage that the friction coefficient does not increase even when tightening is repeated.