... steel industry in China.Produce various of mold steel,tool steel, alloy steel,stainless steel and Round/Square/Flat bar Forging.The usual grade are as below:Plastic Mould Steel ... : S55C, P20(1.2311), 1.2312(P20+S), 718(1.2738/P20+Ni)Hot-working Mould Steel ... ), SUS420(4Cr13)New Mould Steel: Y4(4Cr3Mo2MnVNbB), HD(4Cr3Mo2VNiNbB), HG(4Cr3Mo3W4VNb)Size:Round bar:50mm-1000mmSquare bar ...