Patent ID: 8028870
Filing Date: 2011-10-04
Classification: A61B,C21D,Y10T

Abstract:
1. An eyeless sewing needle, which comprises a curved axial main body extending from a base end to a sharp needlepoint, and which is made of austenitic stainless steel with a fibrous structure in which a crystalline structure of the main body extending axially, and which further comprises an axial hole extending axially from the base end; wherein a periphery of the axial hole at the base end is heated to make the fibrous structure be a granular structure without directionality, and at least a part of a heat-affected zone made between the fibrous structure and the granular structure due to said heating is within a range that is three times the diameter of the sewing needle and that extends from an effective base of the axial hole towards the needlepoint of the sewing needle.