To connect an edge point tip to a base metal by stable high strength.
Relating to a cutter formed by welding an edge point tip 1 consisting of sintered hard alloy and a steel-made base metal 2. So as to obtain a fixed value in a fusing width h1 of the edge point tip 1, a welding center line a is put to a side of the base metal 2 from a boundary line b of the edge point tip 1 and the base metal 2, also in accordance with a total amount of the fusing width h1 of the edge point tip 1 and fusing width h2 of the base metal 2, an amount put to a side of the base metal 2 of the welding center line a is controlled, to perform welding. By obtaining a fixed value in the fusing width h1 of the edge point tip 1, an amount of sintered hard alloy component particularly carbon in a welding part, formed between the edge point tip 1 and the base metal 2 by welding, can be made to a fixed low value, also an influence of rapid heating/cooling of welding to the edge point tip 1 can be decreased.
KUSANO NOBORU
FUWA ISAO
IKEGAMI MASAHIRO
