An assembly includes a simulated nut-and-washer member and a mounting device. The simulated nut-and-washer member includes a base plate simulating a washer, and a cylindrical portion simulating a nut and having a top surface and an outer sidewall with a plurality of faces, the top surface defining a first circular opening having a first diameter. An inner annular surface is disposed radially inward from the outer sidewall and defines a second circular opening disposed coaxial with the first circular opening and having a diameter that is less than the first diameter. The mounting device is configured to be received through the first and second circular openings, and it has a head portion that is configured to contact the inner annular surface.

An assembly includes a simulated nut-and-washer member and a mounting device. The simulated nut-and-washer member includes a base plate simulating a washer, and a cylindrical portion simulating a nut and having a top surface and an outer sidewall with a plurality of faces, the top surface defining a first circular opening having a first diameter. An inner annular surface is disposed radially inward from the outer sidewall and defines a second circular opening disposed coaxial with the first circular opening and having a diameter that is less than the first diameter. The mounting device is configured to be received through the first and second circular openings, and it has a head portion that is configured to contact the inner annular surface.

An apparatus is presented comprising a captive screw comprising an upper portion, an upper middle portion, a central middle portion, a lower middle portion, and a lower portion, the central middle portion comprising a threaded portion, the lower portion comprising a barbed portion, the upper middle portion and the lower middle portion comprising a smooth portion, and the upper portion comprising a grip portion, wherein an outer circumference of the barbed portion is flexible, wherein the captive screw is configured with a first attachment portion and a second attachment portion to attach to a first member of an auxiliary device, and wherein the captive screw is configured to act as a set screw with respect to a second member of an auxiliary device.

An apparatus is presented comprising a captive screw comprising an upper portion, an upper middle portion, a central middle portion, a lower middle portion, and a lower portion, the central middle portion comprising a threaded portion, the lower portion comprising a barbed portion, the upper middle portion and the lower middle portion comprising a smooth portion, and the upper portion comprising a grip portion, wherein an outer circumference of the barbed portion is flexible, wherein the captive screw is configured with a first attachment portion and a second attachment portion to attach to a first member of an auxiliary device, and wherein the captive screw is configured to act as a set screw with respect to a second member of an auxiliary device.

In implementations of a pressure lock retention fastener, the fastener assembly includes an insert sized for insertion into a fastener hole in a first panel. The fastener assembly has a threaded collet sized to slide in the insert and has expandable flanges that extend below the insert. The expandable flanges are sized for insertion into an aligned hole in a second panel. The fastener assembly also includes a screw installable through the insert to engage the threaded collet. The screw exerts a force that pushes the expandable flanges outward as screw rotation drives the screw into the threaded collet, and ridge locks of the expandable flanges seat up against the second panel effective to fasten the panels together. In implementations, a plate is installable between the panels with slotted holes having anti-rotation tabs that prevent a fastener assembly from spinning in the panel holes.

An installing system (100) according to the present disclosure includes a U-bolt (10) which includes a pair of shaft parts (11) aligned in a first direction and extending in a second direction orthogonal to the first direction, and a bridge part (12) that connects one ends of each of the pair of shaft parts (11); and a measurer (20), in which a strain gauge (14) which outputs a signal corresponding to a strain of the shaft parts (11) in the second direction is embedded in each of the pair of shaft parts (11), in line symmetry with respect to a straight line (OX) including an apex (0) of the U-shape and extending in the second direction, and the measurer (20) measures the strain of each of the pair of shaft parts (11) in the second direction, from an output signal of the strain gauge (14) embedded in each of the pair of shaft parts (11).

A U-bolt (10) according to the present disclosure is a U-bolt (10) including a pair of shaft parts (11) arranged in a first direction and extending in a second direction orthogonal to the first direction, a bridge part (12) connecting one end of each of the pair of shaft parts (11) and includes a photonic crystal thin film (14) which is stuck to at least a part of at least one shaft part (11) of the pair of shaft parts (11) and changes its color according to strain of the shaft part (11).

A U-bolt (10) according to the present disclosure is a U-bolt (10) including a pair of shaft parts (11) arranged in a first direction and extending in a second direction orthogonal to the first direction, and a bridge part (12) connecting one end of each of the pair of shaft parts (11) and in which a strain detection pattern is attached to at least a part of at least one shaft part (11) of the pair of shaft parts (11).

A U-bolt (10) according to the present disclosure is a U-bolt (10) including a pair of shaft parts (11) arranged in a first direction and extending in a second direction orthogonal to the first direction, and a bridge part (12) connecting one end of each of the pair of shaft parts (11) and in which a strain detection pattern is attached to at least a part of at least one shaft part (11) of the pair of shaft parts (11).