A fastening structure with two different threads includes: a rod body provided with a first thread and a second thread arranged at an outward protrusion of the first thread, wherein a pitch and a thread width of the first thread are larger than those of the second thread; and an outer member engaged on an outer side of the rod body and provided with a third thread and a fourth thread arranged at an outward protrusion of the third thread, wherein a pitch and a thread width of the third thread are larger than those of the fourth thread, and correspond to those of the first thread, and the pitch and the thread width of the fourth thread correspond to those of the second thread. When the rod body and the outer member are engaged to rotate in an unhindered manner, the first thread is engaged with the third thread, and the rod body and the outer member can be rapidly moved relative to each other. When the rod body and the outer member rotate relative to each other in a hindered manner, the first thread is disengaged from the third thread, the second thread is engaged with the fourth thread, the second thread and the fourth thread are locked with each other, and the rod body and the outer member are fixed with each other.

Disclosed is a fastener assembly comprising at least one of a bolt member and a nut member; and a drive element adapted for engagement by an installation/driving tool, said drive element comprising a body. The body of the drive element is joined either to the bolt member or to the nut member by means of an interposed interlayer structure, the interlayer structure being adapted to fracture in torsional shear and/or tensile stress in response to a relative rotational and/or tensile force applied to the drive element with the installation/driving tool.

Disclosed is a fastener assembly comprising at least one of a bolt member and a nut member; and a drive element adapted for engagement by an installation/driving tool, said drive element comprising a body. The body of the drive element is joined either to the bolt member or to the nut member by means of an interposed interlayer structure, the interlayer structure being adapted to fracture in torsional shear and/or tensile stress in response to a relative rotational and/or tensile force applied to the drive element with the installation/driving tool.

A bolt connection is provided for connecting two flanges. The bolt connection includes a threaded bar extending through a hole of a first flange and a hole of a second flange, the first flange abutting the second flange; an anti-fatigue sleeve; and a nut. The anti-fatigue sleeve is disposed on the threaded bar on the side of the first flange between the nut and the first flange, the nut is configured to be screwed onto the threaded bar and is configured to press the anti-fatigue sleeve against the first flange to fasten the first flange and the second flange together.

A bolt connection is provided for connecting two flanges. The bolt connection includes a threaded bar extending through a hole of a first flange and a hole of a second flange, the first flange abutting the second flange; an anti-fatigue sleeve; and a nut. The anti-fatigue sleeve is disposed on the threaded bar on the side of the first flange between the nut and the first flange, the nut is configured to be screwed onto the threaded bar and is configured to press the anti-fatigue sleeve against the first flange to fasten the first flange and the second flange together.

Provided is a steering device including a lock nut that fixes an outer race of a turning nut threadably engaged with a rack bar. A loosening prevention protruding portion formed on a lock nut main body is brought into contact with a radial-direction abutting portion to prevent loosening of the lock nut with a frictional force. At the same time, a lock nut recessed portion for reducing mechanical stiffness is formed in an outer peripheral surface of the loosening prevention protruding portion so that an external force acting from the outer race is buffered by the lock nut recessed portion. In this manner, a decrease in contact area between the loosening prevention protruding portion and the radial-direction abutting portion is reduced.

A nut-and-bolt fastener is provided. The nut and bolt are configured with a plurality of interlocking teeth that provide unidirectional travel of the nut with respect to the bolt. In particular, the configuration of the teeth arrest separation of the nut from the bolt while permitting the nut to move toward the head of the bolt into a fastened engagement. The teeth are non-helical and arranged concentrically around the longitudinal axis in evenly-spaced steps or segments along the longitudinal axis and around the shaft of the bolt and bore of the nut. Integral winged washers are provided on the bolt head as well as on the nut. Variations with different rake angles of the teeth as well as an expandable nut are also provided.

A fastening nut device for fastening one substrate to another includes a cylinder, which is circumferentially larger proximate to a first end thereof, thus defining a first section and a second section of the cylinder. External threading, which is reversed, is positioned on the second section and extends from a second end of the cylinder. The cylinder can be inserted into a first hole positioned in a first substrate by counterclockwise rotation. The first section of the cylinder abuts a first face of the first substrate and the second end of the cylinder is accessible from a second face of the first substrate. A channel, which is internally threaded, extends into the cylinder from the second end. A threaded fastener, which is engaged to a second substrate, can be inserted by clockwise rotation into the channel to engage the second substrate to the second face of the first substrate.

A fastening nut device for fastening one substrate to another includes a cylinder, which is circumferentially larger proximate to a first end thereof, thus defining a first section and a second section of the cylinder. External threading, which is reversed, is positioned on the second section and extends from a second end of the cylinder. The cylinder can be inserted into a first hole positioned in a first substrate by counterclockwise rotation. The first section of the cylinder abuts a first face of the first substrate and the second end of the cylinder is accessible from a second face of the first substrate. A channel, which is internally threaded, extends into the cylinder from the second end. A threaded fastener, which is engaged to a second substrate, can be inserted by clockwise rotation into the channel to engage the second substrate to the second face of the first substrate.

Pet nail caps cover pets' nails to prevent scratches on surfaces (e.g., hardwood and tiled flooring) and avoid injuries to themselves and others (e.g., pets' eyes and ears, human extremities) while not compromising pet's mobility but rather improving it. The treads on the caps' tips increase the coefficient of friction between the caps (i.e., individual pet's nails) and the hard-surface flooring improving traction and overall pet's mobility. Internal spirals allow the caps to twist onto pets' nails and stay securely attached. A rubber-like material of construction (e.g., thermoplastic elastomers, thermoplastic polyurethane) provides for cap's flexibility and durability.