A metal member to be cast-wrapped by a metal cast article, a manufacturing method
thereof and a metal cast article including the metal member cast-wrapped are provided.
A hollow cylindrical metal member having an outer surface with projections to be
cast-wrapped by a metal cast article is manufactured in such a manner that a hollow
cylindrical metal raw material 13 is inserted in a die 17 having
a inner peripheral surface with longitudinal grooves of a depth H and a width W,
and the hollow cylindrical metal raw material 13 is subjected to hot-extrusion.