A tension indication device for a rock bolt includes a support washer, a cover member having a central hole for receiving a trailing portion of the rock bolt, and an indicator substance provided in a first space in the cover member or in a recess in the support washer for facing the nut. Upon rotation of the nut, indicator substance is forced out of the first space such that the indicator substance is visible at inspection of the rock bolt, thereby indicating that the rock bolt has been tensioned.

Button comprising a nut (1), a support (3) and a cover (5) fitted on the aforesaid support (3) defining a chamber (6) and having at least one window (51, 52) for an indicator for at least one position chosen from a first position for the button roughly corresponding to a minimum tightening torque for the nut (1) and a second position for the button corresponding to a lower tightening torque than the tightening torque for the first position, with the aforesaid indicator (30) being connected to a plate (13) by a tube element (131) which ensures that a rotation of the plate (13) is translated into a rotation of the indicator (30).

A threading indicating bolt comprises a shank and a head, said head defining a trailing end and said shank defining a leading end of said bolt, said shank comprising a threaded trailing portion having a thread pitch, and a threaded leading portion, said threaded leading portion having a thread start, wherein said threaded leading portion extends in the axial length of said leading portion from said thread start to the threaded trailing portion for a length (L) being three times the thread pitch of said threads of said trailing portion; and wherein a torque is needed to thread a matching nut onto said bolt; said leading portion of said bolt comprising a mechanical threading indicating element adapted to increase said torque needed to thread a matching nut onto said bolt, while said matching nut is in threaded engagement with the mechanical threading indicating element arranged on said leading portion of said bolt; said increase of said torque being in comparison to a required run-down torque when said matching nut has been threaded onto said bolt past said leading portion and onto said threaded trailing portion. A threading indicating system and a method for assembling a bolted joint are also disclosed.

A threading indicating bolt comprises a shank and a head, said head defining a trailing end and said shank defining a leading end of said bolt, said shank comprising a threaded trailing portion having a thread pitch, and a threaded leading portion, said threaded leading portion having a thread start, wherein said threaded leading portion extends in the axial length of said leading portion from said thread start to the threaded trailing portion for a length (L) being three times the thread pitch of said threads of said trailing portion; and wherein a torque is needed to thread a matching nut onto said bolt; said leading portion of said bolt comprising a mechanical threading indicating element adapted to increase said torque needed to thread a matching nut onto said bolt, while said matching nut is in threaded engagement with the mechanical threading indicating element arranged on said leading portion of said bolt; said increase of said torque being in comparison to a required run-down torque when said matching nut has been threaded onto said bolt past said leading portion and onto said threaded trailing portion. A threading indicating system and a method for assembling a bolted joint are also disclosed.

A device for torque limiting, has a nut having a female thread. A holding element includes a top part having an entrainment profile in a rear area of the holding element for the rotatably fixed coupling of the top part with a setting tool and a receiving part having a receptacle in a front area of the holding element, in which the nut is rotatably fixedly accommodated, the top part having a passage, through which a threaded rod screwed into the nut may be led out of the holding element through the top part along the longitudinal axis of the device. The holding element includes a web connecting the receiving part and the top part and which forms a predetermined breaking point. In at least one longitudinal sectional plane of the device, the smallest wall thickness of the at least one web is present on a line segment of minimum wall thickness, which runs at an angle greater than 45° with respect to the longitudinal axis of the device. A fastening arrangement includes the device.

The invention relates to a solution for how to measure the strain in a washer mounted in a bolt assembly comprising a bolt, nut and washer. The invention concerns a strain measuring washer assembly comprising a plate shaped washer body, sound emitting means and sound detecting means, and a method for using such.

A direct tension indicating washer apparatus includes a direct tension indicating washer; a base washer; and an anti-rotation feature to prevent rotation of the direct tension indicating washer relative to the base washer.

A direct tension indicating washer apparatus includes a direct tension indicating washer; a base washer; and an anti-rotation feature to prevent rotation of the direct tension indicating washer relative to the base washer.

A monitoring system includes a fastener. A sensor is coupled to the fastener. A circuit board is electrically coupled to the sensor. An antenna electrically coupled to the circuit board.

The disclosure relates to a shearing screw for clamping an electrical conductor within a cable connector. The shearing screw comprises a screw body for engaging the cable connector, which further comprises an outer thread and a clamping surface for clamping the electrical conductor within the cable connector. The screw body also comprises a collar and a groove for detaching the collar from the screw body, whereas the shearing screw comprises a nut for shearing the shearing screw. The collar and the nut are adapted to be rotatable simultaneously with a sleeve for fastening the shearing screw to the cable connector.