A guide hole is constituted of a large-diameter hole, a medium-diameter hole, and a small-diameter hole. A sliding part fitted in the guide hole is formed of a synthetic resin material. A large-diameter portion of the sliding part is fitted in the large-diameter hole in a slidable state, and a medium-diameter portion is fitted in the medium-diameter hole in a slidable state. A movable end surface of the sliding part is in close contact with a stationary inner end surface of the guide hole. By configuring a width dimension of the movable end surface to be less than half of a thickness dimension of the large-diameter portion, a pressurizing force of the movable end surface is increased and a minute metal piece is pushed from the movable end surface into a base material of the sliding part, and a thickness dimension of the medium-diameter portion is set large.

A welding auxiliary joining part with which a welding connection, more particularly a resistance welding connection, can be established between a first component A made of a poorly weldable material and a second component made of weldable material. The welding auxiliary joining part is distinguished by a cylindrical punch shaft that can be punchingly pressed into the first component A approximately rotation-free. The punch shaft has an element head at the head underside of which only one continuous circumferential clamping ring is arranged that projects axially in the direction of the punch shaft.

Provided is a projection bolt welding method, which involves welding a projection bolt to a steel sheet component by electric resistance welding. The projection bolt includes a shank, a circular enlarged diameter portion, and a welding projection including an initial fusion portion with a tapered portion and a main fusion portion. A ratio of a volume of the initial fusion portion to a volume of a portion of the steel sheet component having the same diameter as a diameter of the initial fusion portion is selected, or a ratio of a circular area of the initial fusion portion to a sheet thickness of the steel sheet component is selected.

Provided is a projection bolt welding method, which involves welding a projection bolt to a steel sheet component by electric resistance welding. The projection bolt includes a shank, a circular enlarged diameter portion, and a welding projection including an initial fusion portion with a tapered portion and a main fusion portion. A ratio of a volume of the initial fusion portion to a volume of a portion of the steel sheet component having the same diameter as a diameter of the initial fusion portion is selected, or a ratio of a circular area of the initial fusion portion to a sheet thickness of the steel sheet component is selected.

An apparatus includes a housing, a mechanism and a sensor. The housing may be configured to receive a weld head. The mechanism may be attached to the housing and configured to convert a position of a location pin relative to the housing into an angular rotation. The sensor may be coupled to the mechanism and configured to generate a value representative of the position of the location pin based on the angular rotation.

A welding electrode unit includes a repositioning device that is movable. The repositioning device includes an energy storage device by way of which a welding electrode is connected directly or indirectly with the energy storage device can have a force applied to it for the purpose of a repositioning movement. The repositioning device is movable into a welding position by way of a forward movement and can be locked in the welding position.

A welding electrode unit includes a repositioning device that is movable. The repositioning device includes an energy storage device by way of which a welding electrode is connected directly or indirectly with the energy storage device can have a force applied to it for the purpose of a repositioning movement. The repositioning device is movable into a welding position by way of a forward movement and can be locked in the welding position.

A welded steel door including a pan having a bottom surface forming a first face of the door and flanges extending on opposite edges thereof forming opposite side edges of the door, the flanges having a lid engaging surface spaced from the bottom surface, a lid having a top surface forming a second face of the door opposite the first face, opposite edges of the top surface each having a hem mated with a respective lid engaging surface of each flange, the hem including a portion of the top surface folded back on itself, and a plurality of welds securing the lid to the pan. The welds extend between the portion of the top surface of the lid folded back on itself of each hem and the respective lid engaging surface of each flange and are thereby concealed.

A welded steel door including a pan having a bottom surface forming a first face of the door and flanges extending on opposite edges thereof forming opposite side edges of the door, the flanges having a lid engaging surface spaced from the bottom surface, a lid having a top surface forming a second face of the door opposite the first face, opposite edges of the top surface each having a hem mated with a respective lid engaging surface of each flange, the hem including a portion of the top surface folded back on itself, and a plurality of welds securing the lid to the pan. The welds extend between the portion of the top surface of the lid folded back on itself of each hem and the respective lid engaging surface of each flange and are thereby concealed.

A joining structure includes a first member, a second member of a material different from that of the first member, and a separation mechanism provided between the first member and the second member and that separates the first member and the second member from each other, wherein a resin is filled into the space between the edge of at least one member among the first member and the second member, and the other member.