To provide a bore pin for casting a cylinder block, wherein the positional accuracy of formation of a cylinder bore is maintained satisfactorily and the durable service life is longer in comparison with the conventional material by improving the wear resistance on the surface of the bore pin.

The bore pin is used for inserting into a liner when the cylinder block is cast, wherein at the portion in contact with at least the liner in a base material composed of a metal material forming a recessed part at a part of the outer surface, a coating layer composed of a high speed steel-base alloy is formed as cast-in method. The above coating layer is composed of an Fe-base alloy containing by mass% of 1.0-3.0% C, 0.1-2.0% Si, 0.1-2.0% Mn, 0-4.5% Ni, 3.0-10.0% Cr, 0-9.0% Mo, 0-10.0% W and 1.0-10.0% V.