A fastening structure inserts a threaded rod 11a of a bolt 11 through a fixing hole 12a of a to-be-fixed member 12 in a manner such that an end portion of the threaded rod protrudes from the fixing hole, and screwing a machine screw 15 with a proper torque into a nut 14 which is provided on the end portion via a washer 13. The washer has an inclined surface 13c formed on a first side 13b which faces the nut, and has a flat surface formed on a second side 13d. The machine screw is screwed into the nut in a direction such that an axis is orthogonal to the inclined surface 13c. The first side (the inclined surface) and the second side of the washer have a different surface roughness, and the first side has a smaller coefficient of friction than the second side.

A hand tool for bolts fastening includes a block-shaped jig body, a first bolt hole is disposed in the jig body laterally and a second bolt hole is disposed in the jig body longitudinally, an end of the second bolt hole is in communication with the first bolt hole, the second bolt hole allows a packing bolt to pass through and be screwed, a hemispherical suppression portion is disposed at an end of the packing bolt, the first bolt hole allows a to-be-fastened bolt to be screwed, the suppression portion of the packing bolt is pressed down on a selected position of the bolt, to cause a crest at the selected position to expand outward, so that interference occurs when the bolt is screwed with a bolt hole or a nut, to increase a torque force required to make the bolt come off.

A method of repairing a chain can include aligning a bore of an outer chain link with a bore of an inner chain link, inserting a pin through the aligned bores, the pin having a thread end opposite a head end, engaging a multi-jackbolt tensioner with the thread end of the pin, the multi-jackbolt tensioner having a plurality of fasteners, advancing each of the plurality of fasteners to press on the outer chain link, and forming an interference fit between the pin and the outer chain link at the bore of the outer chain link from the advancing of the fasteners.

A machine element includes individual ring components (10, 12) fastenable to third components, such as axles, shafts, or hubs. One ring component can be actuated toward another ring component in an advancing motion by an adjusting device (18) in an axial direction (Y). An angled force application to the one ring component (10) in a tilted direction (24) that deviates from the axial advancing direction (Y) occurs by the adjusting device (18) for the advancing motion. The ring component that is exposed to the angled force application follows the tilted direction by a contact surface (30) for the contact with the adjusting device (18). In a thread-free segment of the adjusting device (18), the adjusting device has a titled control surface (32). The adjusting device then follows the contact surface (30) with its tilted direction (24) when the adjusting device (18) is actuated.

The present invention relates to a bolt structure including: a base bolt having one side end portion inserted into holes formed at the time when a fixed structure and an object to be fixed are laid on top of each other; a core bolt adapted to be advanceably and retreatably screw-coupled to the base bolt; a nut fastened to the end portion of the base bolt protruding from the holes to maintain the state where the fixed structure and the object to be fixed are laid on top of each other; locking units adapted to selectively pressurize the external surface of the nut to prevent the escape of the base bolt; and a restraint unit adapted to be advanceably and retreatably screw-coupled to the base bolt and come into contact with the end portion of the core bolt to restrain the advancement and retreat of the core bolt.

A thread locking mechanism may be include in a threaded portion of a removable part to enable the removable part to be securely locked to an assembly such that the removable part does not turn when another part is being attached or removed. The thread locking mechanism may also be un-locked when it is desirable for the removable part to turn and be removed from, or further secured to, the assembly. In some examples the removable part may be an oil filter adapter, the assembly may include an engine, and the other part may be an oil filter.

Provided is an insert member for an open end wheel nut, which is capable of improving the workability of dressing up the car in the case of mounting a wheel using the open end wheel nuts. An insert member 1 for an open end wheel nut includes a shaft body 2 provided on an outer periphery thereof with a male thread 2a to be screwed on a female thread portion 10a of an open end wheel nut 10 from one end thereof. The shaft body 2 includes: a hexagonal hole 5 provided at an opening on the one end of the open end wheel nut 10; and a recess 2b provided at an opening on the other end of the open end wheel nut 10. A spring 3 that urges the shaft body 2 in an axial direction thereof is provided in the recess 2b.

A wheel nut assembly for fixing a wheel to a vehicle hub which includes a wheel nut with an internal thread and an axial body extension on said nut including a first section with an internal set of axial grooves or ribs and a second section containing a second internal screw thread. There is also a wheel stud having an external thread to co-operate with the internal thread of said wheel nut and having an end portion adapted to project beyond the wheel nut which end portion includes axial grooves or ribs on its external surface. An axial retaining cap consists of an upper externally screw threaded first portion which is adapted to engage the second internal screw thread of said body extension of said nut and attached to said first portion a second cap portion having internal grooves or ribs complementary to the external ribs or grooves on said wheel stud adapted to fit over said wheel stud and having external ribs or grooves adapted to engage the internal set of axial grooves or ribs on the first section of said body extension of said wheel nut. The first portion of said retaining cap is able to be rotated so that it moves axially down the internal screw thread of the second section of said body extension of said wheel nut so that the second portion of said cap is pushed down the end of said wheel stud and is held between the external ribs and grooves of the end of said wheel stud and the internal ribs and grooves of the first section of said body extension of said wheel nut.

A locking system and a manufacturing method thereof, a bearing assembly, and a robot having the same. The locking system incudes a first nut arranged on a shaft and adapted to contact with an upper side of an inner ring of the bearing. The locking system can also include a second nut arranged on the shaft and separated from the first nut at a predetermined distance. The locking system can include a locking screw adapted to be screwed through a first through hole of the second nut and a second through hole of the first nut while the first through hole and the second through hole are aligned with each other.

A tamper-proof screw includes a main body, a pin body, a ball, and at least one abutting member. A through hole is provided in the main body. The pin body is movably disposed in the through hole. The ball is located in the through hole. The abutting member is located in the through hole and has a connecting end and a free end opposite to each other. The connecting end is disposed on an inner wall of the main body and located between the ball and the free end. The ball is located between the pin body and the abutting member. When the pin body moves in the through hole to push the ball to press against the connecting end of the abutting member, the abutting member pivots around the connecting end to allow the free end to extend outwards from the main body.