practical uses not enjoyed by other treatments such as plating spraying and thermal hardening treatments these other treatments require complicated processes such as masking or channelling when put to practical use on the other hand the re melting treatment produces a heat effected layer 72 peripherally of the re melting treated layer 7 as shown in fig7 to provide higher hardness in proportion to the portion as hardened the present invention which makes use of the difference in abrasion amount serves to heighten its effect more particularly an edge 87 fig4 formed at the boundary between the wear treated layer 7 and the exposed surface of the base metal 8 as shown in fig4 is likely to scratch an opposing sliding member and break off however in the present invention since the thermally effected layer whose hardness is substantially similar to that of the layer 7 is provided adjacent to the latter acute edge generation can be obviated the hardening treatment based on re melting and cooling is adapted to act as a treatment making cast iron into white cast iron when cast iron is used as the base metal and functions as a treatment making steel into martensite by recrystallization and densifying steel when the latter is used as the base metal in.