| 摘要 |
PURPOSE:To prevent the breakage of a welded part or bending at an acute angle due to a crack, by softening the periphery of the welded part of a pipe and a needle both of which are made of stainless steel to bring the same to a state near to the hardness of the welded part. CONSTITUTION:A needle main body 1 and a pipe 2, both of which are made of 18-8 stainless steel having no quench hardenability such as SUS 302 or SUS 304, are welded at a welded part 3 by laser beam to constitute an eyeless suture needle. A burner 8 such as a propane gas burner is used and the periphery of the welded part 3 of the suture needle and the almost whole of the pipe 2 are heated to about 1,000 deg.C by the flame of the burner 8 and softened. As a result, the periphery of the welded part 3 and the whole of the pipe 2 can be constituted softly so as to have hardness of about 200-280. By this method, it can be perfectly prevented that a crack is generated in the welded part of the suture needle to generate breakage or bending at an acute angle, even when bending stress is applied to the suture needle at the time of use. Further, caulking for mounting a suture is made easy. |
