GJP bearing ferrule and steel ball are made of refined GCr15 bearing steel, the retainer is made of brass belt(H62) or cold-rolled steel belt(SPCC BQB402) by pressing(or strengthened engineering plastics if necessary), the dustproof cover is made of special imported material(SPCC JISG3141) or stainless steel belt(ICr18Ni9), and the sealing loop is made of phosphated steel frame and BUNa-N by hot pressing.   Chemical composition of bearing steel and stainless steel: Steel No. C% Si% Mn% S% P% Cr% GCr15 0.95-1.05 0.15-0.3 0.25-0.45 <0.025 <0.025 1.3-1.6 9Cr18 0.90-1.05 <0.8 <0.8 <0.04 <0.03 16-19 Cross reference table of bearing steel model of different countries: Country China ISO U.S.A Germany japan Sweden Bearing Steel Number GCR15 683/X (AISI)52100 (Din£©100Cr6 (Jis)SUJ-2 SKF3