A mechanical coupling assembly that includes a primary substrate having at least one aperture formed therein. A secondary substrate includes at least one mechanical interlock monolithically formed with the secondary substrate. The at least one mechanical interlock extends through the aperture. The mechanical interlock includes a main body and a head portion with a transition portion connecting the main body and head portions. The main body includes a bore formed longitudinally therein about a centerline of the aperture. The mechanical interlock joins the primary substrate and secondary substrate mechanically.

A joining tool unit including a hold-down device, a linearly movable tool, and a tool counter element. The hold-down device and the tool counter element are provided opposite each other, a workpiece lies on the tool counter element when the workpiece is arranged on the joining tool unit, and the hold-down device is arranged to be supported on a surface of the workpiece. The hold-down device has a light-guiding system, and the light-guiding system is designed to guide a light beam of a light in the direction of a joint location of the workpiece when the workpiece is arranged on the joining tool unit. The light-guiding system is provided on the hold-down device such that the light beam is irradiated onto the joint location solely at an angle which is greater than 0 relative to a movement axis of the linearly movable tool.

An electric power tool is disclosed. In an embodiment, the electric power tool includes a tool, a tool holder part and a main body with a plurality of rivets integrated with the main body. The rivets include rivet shafts of a cross section for producing a positive-locking rivet joint of the tool with the tool holder part, wherein the tool and the tool holder part have circular openings which are aligned with each other, and wherein the rivet shafts are positioned aligned with the openings on the main body and protrude through the aligned openings.

A blind fastener for connecting workpieces includes a bolt and nut. The bolt includes a shaft, bolt head, and lug. The bolt head is between the shaft and lug and extends radially outward from the shaft. The shaft defines external threads opposite the bolt head. The lug includes a first tool engagement portion and a first frangible portion that frangibly couples the lug to the bolt head. The nut includes a sleeve, nut head, and handling member. The shaft is threadably received in the sleeve. The nut head extends radially outward from the sleeve and defines a recess that receives the bolt head. The handling member surrounds at least a portion of the lug. The handling member includes a second frangible portion and a second tool engagement portion. The second frangible portion frangibly couples the second tool engagement portion to the nut head.

A wearable protection device including a modular frame with at least two shaped members and hinge means for hinging the shaped members therebetween at corresponding hinging points and around respective rotation axes. Each of the hinge means includes a pivot element and a disc element which are permanently coupled by riveting of the pivot element. After the riveting, the pivot element (12) is closely aligned or flush with the disc element. Also provided is a method of assembling said wearable protection device and a motorcycle boot including the wearable protection device.