| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a backing strip having such a structure as to prevent occurrence of fall-off of a molten metal in the vicinity of R-shaped parts of the backing strip in final welding by expanding the interval between grooves of the parts becoming into the R shape when folded.SOLUTION: A backing strip 1 is used by folding a pair of belt-like metal sheets to form a rectangular frame. Individual grooves 3 are formed continuously by forming deep and narrow grooves continuously in the longitudinal direction in parts that each are to be the inside of an R shape area by a cutter and then by performing cutting shallowly with a wide edge from over the deep and narrow grooves, in order to form level differences of different widths in such a way that the groove widths of the grooves 3 become wider from the lower part, or the groove bottom, toward the upper part in the longitudinal direction of the body.</p> |
