1.premachined ring blanks 2.Specialized for 10 years 3.Certified by ISO,GL,ABS 4.Heat treatment:N+Q+T 5.MOQ for 1Pc 1.Features: pre-machined steeel rings with heattreatment2.Stabdards: ASME,ASTM,GB,JIS,DIN3.Materials: carbon steel,stainless steel and alloy steel.4.Certificates: ISO,GL and ABS5.OD: from 100mm to 5000mm 6.Min Order:for 1 pc7.Delivery time:about 20days from your order8.Competitive ...