This disclosure relates to weldability of steel alloys that provide weld joints which retain hardness values in a heat affected zone adjacent to a fusion zone and which also have improved resistance to liquid metal embrittlement due to the presence of zinc coatings.

A ring forming step includes welding opposite ends of a band saw blade including a body part having a band shape, and a tooth part including a plurality of teeth formed on one side part of the body part, to form a ring shape. A polishing step includes polishing an inner surface, an outer surface, and an end face on a side opposite to the tooth part in the ring-shaped band saw blade subjected to the ring formation. A tip tooth tip forming step includes positioning, after the polishing step, the ring-shaped band saw blade subjected to the ring formation by use of one of the inner surface and the outer surface, and the end face as references, joining a cutting tip to tooth tips of the plurality of teeth by welding, and polishing the joined cutting tip to form a tooth tip shape.

A ring forming step includes welding opposite ends of a band saw blade including a body part having a band shape, and a tooth part including a plurality of teeth formed on one side part of the body part, to form a ring shape. A polishing step includes polishing an inner surface, an outer surface, and an end face on a side opposite to the tooth part in the ring-shaped band saw blade subjected to the ring formation. A tip tooth tip forming step includes positioning, after the polishing step, the ring-shaped band saw blade subjected to the ring formation by use of one of the inner surface and the outer surface, and the end face as references, joining a cutting tip to tooth tips of the plurality of teeth by welding, and polishing the joined cutting tip to form a tooth tip shape.

An electric resistance welded steel pipe or tube comprises: a base metal being a steel sheet having a specific chemical composition and an electric resistance weld portion having a bond width of 40×10.sup.−6 m or more and 120×10.sup.−6 m or less, wherein C.sub.0-C.sub.1 is 0.05 mass % or less, where C.sub.0-C.sub.1 is a difference between C.sub.1 in mass % which is a minimum C content of the electric resistance weld portion and Co in mass % which is a C content of the steel sheet, and a depth of a total decarburized layer in each of an inner surface layer and an outer surface layer of the electric resistance welded steel pipe or tube is 50×10.sup.−6 m or less.

Method for welding two stainless steel sheets of thickness (e) 0.10 to 6.0 mm and having a particular composition having: a first welding step lasting a time (t) in ms: 0.10 to 0.50 mm, t=(40×e+36)±10%; 0.51 to 1.50 mm: t=(124×e 13)±10%; 1.51 to 6.0 mm: t=(12×e+47)±10%; with clamping force (F) in daN: 0.10 to 1.50 mm: F=(250×e+90)±10%; 1.51 mm to 6.0 mm: F=(180×e+150)±10%; appling a current between the welding electrodes, of intensity between 80 and 100% the maximum permissible intensity corresponding to expulsion of molten metal; a second step with an intensity between zero and 1 kA; and a third step with an intensity of 3.5 kA to 4.5 kA, for a time of at least 755 ms.

Method for welding two stainless steel sheets of thickness (e) 0.10 to 6.0 mm and having a particular composition having: a first welding step lasting a time (t) in ms: 0.10 to 0.50 mm, t=(40×e+36)±10%; 0.51 to 1.50 mm: t=(124×e 13)±10%; 1.51 to 6.0 mm: t=(12×e+47)±10%; with clamping force (F) in daN: 0.10 to 1.50 mm: F=(250×e+90)±10%; 1.51 mm to 6.0 mm: F=(180×e+150)±10%; appling a current between the welding electrodes, of intensity between 80 and 100% the maximum permissible intensity corresponding to expulsion of molten metal; a second step with an intensity between zero and 1 kA; and a third step with an intensity of 3.5 kA to 4.5 kA, for a time of at least 755 ms.

Provided is a resistance spot welding method wherein main current passage includes two or more electrode force application steps including a first electrode force application step and a second electrode force application step following the first electrode force application step, an electrode force F.sub.1 in the first electrode force application step and an electrode force F.sub.2 in the second electrode force application step in the main current passage satisfy a relationship F.sub.1<F.sub.2, and an electrode force switching point T.sub.f from the first electrode force application step to the second electrode force application step in the main current passage is set to satisfy predetermined relational formulas.

Provided is a resistance spot welding method wherein main current passage includes two or more electrode force application steps including a first electrode force application step and a second electrode force application step following the first electrode force application step, an electrode force F.sub.1 in the first electrode force application step and an electrode force F.sub.2 in the second electrode force application step in the main current passage satisfy a relationship F.sub.1<F.sub.2, and an electrode force switching point T.sub.f from the first electrode force application step to the second electrode force application step in the main current passage is set to satisfy predetermined relational formulas.

A cap tip assembly for spot welding is disclosed. The cap tip assembly for spot welding is configured to spot-weld a first base material in which a flange is formed and a second base material overlapping the flange in a vertical direction. The cap tip assembly for spot welding includes a tip body provided in a shape of a rectangular block in which a round-shaped welding section is formed on a front side of a top surface, and a collet member coupled to the tip body to guide a conductive tape to the welding section.

A manufacturing method for a cylinder device which includes a cylinder, a piston, a piston rod, a seal member, and an installing member, the method includes: a welding step for fixing the installing member to the cylinder through electrical resistance welding; a demagnetizing step for demagnetizing at least an opening portion of the cylinder; and an assembling step for assembling the piston, the piston rod, and the seal member in the cylinder through the opening portion.