WIRE ROD FOR I-TYPE OIL RING, AND ITS MANUFACTURING METHOD

摘要

Provided is a wire rod for an I-type oil ring, which includes right and left rail portions and a web portion connecting the rail portions, which has an oil hole or a molten through hole formed in the web portion, and which has a circumscribing circle diameter of 10 mm or less in its transverse contour. The molten through hole has such a remolten portion formed on its exit side as encloses the exit of the molten through hole. The remolten portion exceeds such a molten portion in the transverse section along the center of the molten through hole as is formed in the molten through hole, and is formed to have 200 µm or less from the outer circumference of the molten through hole and 100 µm or less in the depth direction of the molten through hole.