US Patent 7802813 Tubular part

A tubular part for fixing and holding a fixing object part inserted therein, the fixing object part being fixed by inwardly crimping a circumferential wall on a side of one end opening of the tubular part, including: the tubular part having a chamfered corner on an inner peripheral side of the circumferential wall on the side of one end opening, a degree of chamfering being such that chamfering is performed between a point at a thickness T1 measured from an outer circumferential surface of the one end opening and a point at a length L1 measured from an end surface of the opening, and when a thickness of the circumferential wall of the opening is represented as T, (T−T1)/T being 0.05 to 0.9 and (T−T1)/L1 being 0.8 to 1.2.