PURPOSE: To increase the joining strength of a segment and base metal by composing a base layer by an Ni alloy, and welding this to the base metal.

CONSTITUTION: A sintered body having a double-layer structure of an abrasive grain layer 1a containing abrasive grains 5 and a base layer 1b containing no abrasive grains and composed of a nickel alloy is made a segment 1. This segment 1 is arranged at the peripheral edge of a disk like base metal 2, an electron beam or laser beam is radiated on the border of this base layer 1b and base metal 2, the segment 1 is welded to the base metal 2, and a desired rotary cutter is made.