A fastener and a system, apparatus, and method for monitoring a fastener are described. The fastener includes a head portion, a shank portion, a transponder, and a compression spring, wherein the head portion includes a mounting portion, and wherein the transponder is disposed in the mounting portion of the head portion. The transponder is arranged to monitor the shank portion, and includes an ultrasonic sensor and a signal processing circuit. The ultrasonic sensor is affixed to a transducer hosting surface, and is urged against the transducer hosting surface by placement of the printed circuit board in the head portion with the compression spring intervening therebetween. The ultrasonic sensor communicates with the signal processing circuit via the compression spring. The signal processing circuit captures a signal from the ultrasonic sensor and transforms the signal into a parameter corresponding to a tensile force being exerted by the fastener.

A torque-limiting nut is provided. The torque-limiting nut is a unitized assembly with a washer, a threaded component, and a tool interface. A reverse thread protector engages the tool interface and washer to inhibit reverse threading once the nut is seated.

A torque-limiting nut is provided. The torque-limiting nut is a unitized assembly with a washer, a threaded component, and a tool interface. A reverse thread protector engages the tool interface and washer to inhibit reverse threading once the nut is seated.

A safety shear bolt includes a main bolt portion and a torque head portion connected to the main bolt portion. The torque head portion includes an extended head portion, a stem portion rigidly connecting the main bolt portion to the torque head portion, and a coupling mechanism rotatably connecting the extended head portion to the main bolt portion. The stem portion is configured to shear when a predetermined torque is applied to the extended head portion, while the coupling mechanism prevents the extended head portion from dropping after shearing off from the main bolt portion.

The invention relates to an improved bolt apparatus for installation, the improved bolt apparatus including, a bolt having a head, shaft and an end and the head of the bolt including an improvement means. The bolt also including an engagement means, associated with the shaft, between the head and the end of the bolt, for engaging with or into a surface where the bolt is to be installed. The improved bolt apparatus may be installed into a suitable hole in the surface, and the improvement means enables the type, kind, or characteristic of the bolt to be known and or the bolt installation to be adjusted within the hole. The invention also provides many variants thereon, and methods of use.

The invention relates to an improved bolt apparatus for installation, the improved bolt apparatus including, a bolt having a head, shaft and an end and the head of the bolt including an improvement means. The bolt also including an engagement means, associated with the shaft, between the head and the end of the bolt, for engaging with or into a surface where the bolt is to be installed. The improved bolt apparatus may be installed into a suitable hole in the surface, and the improvement means enables the type, kind, or characteristic of the bolt to be known and or the bolt installation to be adjusted within the hole. The invention also provides many variants thereon, and methods of use.

Disclosed is a method of adapting a metal bar, for use as a rock bolt, to ensure that the bar will break in a predictable manner, the method including the step of removing material from the bar in a circumferential band to reduce a diameter of the bar within the band to a minor diameter thereby to provide a failure zone within which the bar will break if subjected to enough tensile load.

An adapter for a cable hanger includes: a housing having a floor, a vertical wall extending generally perpendicularly from the floor, and side walls extending generally perpendicularly from the floor and vertical wall, each of the side walls including a finger extending generally parallel to the floor, the fingers including first engagement features, the vertical wall including a mounting hole; and a plunger having a main panel and second engagement features on opposite sides of the main panel, the second engagement features configured to engage the first engagement features to restrict relative movement of the plunger relative to the housing.

A fastener structure includes a head, a fastening portion and a twist break portion. The twist break portion is fastened at an object by the fastening portion, or is fastened at another object through the object by the fastening portion. Once the fastening portion is fastened, the twist break portion is twisted and broken. Thus, the fastener structure of the present disclosure is capable of providing a required object with a stable combining effect.

A screw having stacked screw heads includes a screw shank portion with a thread and a screw head portion rigidly connected to each other. The screw head portion is driven to bring the screw shank portion to rotate. The screw head portion includes a first screw head and a second screw head. The first screw head has a first shaped groove on its top plane to receive an operating torque. A neck portion is connected to a bottom plane of the first screw head and a top plane of the second screw head. The second screw head has a second shaped groove on its top plane. The neck portion or the connection between the neck portion and the first screw head or the second screw head has lower torsional endurance than each of the first screw head and the second screw head.