SUBSTANTIALLY CYLINDRICAL POWDER COMPACT AND POWDER DIE DEVICE

摘要

The cross-sectional shape of a main part except for both end portions is generally divided into a lower arc-shaped face (12) extending along a base circle (P) and an upper arc-shaped face (12) of which top portion corresponds to the base circle (P). Side edge portions (15) extending inward from the base circle (P) are formed at side surfaces (14) of either side of the upper arc-shaped face (12). Curved edge portions (15a) concavely warped upward from the side edge portions (15) to end faces (10) so as to communicate with the end faces (10) and chamfered end portions (16) extending from the end faces (10) to the side surfaces (14) as to be curved in such a manner that the width thereof is gradually reduced are formed at both end portions in the longitudinal direction.