Abstract: In a molten metal plating apparatus all surfaces of a sinking roller and a supporting roller to be in contact with a molten metal are coated with iron silicide films. A bearing comprises a holder made of a heat resistant steel and lined with a carbon-carbon fiber complex material. A surface of the holder is coated with an Fe3Si film similar to the sinking roller. There is an Fe3Si film on a surface of a shaft portion, and the Fe3Si is in contact with and slides on the carbon-carbon fiber complex material.

Abstract: A compound roll for a metal rolling mill having both excellent resistance to a thermal shock crack and excellent wear resistance includes a core shaft made of low alloy steel and an outer layer consisting of high speed tool steel having a composition, by weight percent, essentially of 0.5 to 1.5% of C, 0.5 to 3.0% of Si, 1.5% or less of Mn, 2 to 7% of Cr, 1 to 5% of Mo, 0.5 to 2.0% of V, up to 2.0% of W and balance essentially Fe. The outer layer is formed on the outer surface of the core shaft by an electro-slag method. The outer layer is subjected to a water jet spray quenching and tempering at 300.degree. C. or higher, preferably 450.degree. C. to 550.degree. C.

Abstract: A continuous hot-dip plating apparatus has a roll assembly having superior resistance to erosion caused by the hot melt plating metal, as well as high resistance to wear of the shaft and bearings, which are immersed in the hot melt of the plating metal. A ceramic material is mounted on the sliding portions of the metallic roll shaft to make sliding contact with the metallic bearings and/or on the sliding surfaces of the metallic bearings which contact the metallic roll shaft. A clearance is left between the shafts and bearings to hold molten metal thereinbetween for lubrication.