Nitrided valve lifter

摘要

A sliding surface ( 2 ) of a valve lifter ( 1 ) or a shim ( 3 ) is subjected to a gaseous nitriding to have a surface hardness of Hv 660 or higher and a thickness of a compound layer ( 6 ) of 1 to 5 mum. The nitrided layer on the surface is a dense compound layer ( 6 ) with a porosity of 5% or less.