PURPOSE: To simplify the process for producing a piston pin and to reduce the cost of production by packing reinforcing fibers into the hollow part of a steel pipe subjected to a hardening treatment, immersing the pipe into a molten Al alloy to infiltrate the Al alloy among the fibers and tempering the pipe.

CONSTITUTION: A steel pipe 1 is subjected to an oil hardening treatment and thereafter reinforcing fibers 2 are packed at about 50% packing density in the hollow part 1a thereof. The fibers 2 are made to have about 15W17μ diameter and about the same length as the length of the pipe 1, and alumina fibers, etc. are used. The pipe 1 is then immersed for about 10W60min in a molten Al alloy 4 kept at about 630W720°C and disposed into an autoclave 3 to be exerted with high vapor pressure to infiltrate the Al alloy among the fibers 2 and to temper the pipe 1 by the heat of the molten alloy 4. The pipe 1 is taken out and is air- cooled in the atm. and thereafter the pipe is subjected to grinding.