PURPOSE: To prevent burrs or chipping from being generated even when the top end part of a bayonet tip hits a needle by improving strength for the top end part of the bayonet tip.

CONSTITUTION: A fitting part 7 is formed at the top end part of a bayonet chip 3, and a fine chip 4 equipped with an acute angle part 4e for hanging an upper thread at the time of sewing work is formed by using a material of which hardness and flexibility is higher than that of a material for a main body 2 of the outer shuttle. Then, the fine chip 4 is fitted to the fitting part 7 while turning the acute angle part 4e forward along the rotating direction of the outer shuttle and after this fitting, a grinding margin part 10 of the bayonet tip 3 is ground so that a slope part 4c of the fine chip 4 and the front edge of the bayonet tip 3 can be continued with no step.