Patent ID: 6870953

Claim:
A method of sorting out defect-free workpieces blanked out of a metal sheet, comprising the steps of: inserting the workpieces into a passage having a predetermined width to sort out those workpieces which have passed through said passage; analyzing respective images of the workpieces which have passed through said passage to compare the images with a reference workpiece image, reject workpieces which have a portion different from said reference workpiece image, and sort out other workpieces; and applying a gauge having a shape complementary to a required shape for a functional portion of the workpieces, to the workpieces which have been sorted out, and sorting out those workpieces whose functional portion has a shape complementary to the shape of said gauge, as defect-free workpieces, wherein said step of applying a gauge, further comprises the step of inserting a pair of gauge portions of said gauge into respective recesses formed in the workpieces, said recesses being formed between a body and a head of the workpieces.