Productname:TwinConicalscrewsandbarrels Size:Diameter35/75-92/188mm Material:38CrMoAlA;SKD61;SKD11;40Cr;42CrMo;highqualityalloysteel Technology:nitridingtreatment,alloycoatingspraying,heat-treatment Appliance:PA,EVOH,EAA,PCetc TechnicalIndex: DepthofNitratedLayer:0.5-0.8mm Hardnessofnitration:900-1020Hv Fragilityofnitration:Lessthangrade1 SurfaceHardnessofNitratedCrcoatinglayer:≥950Hv HardnessofBimetallicLayer:HRC55°-72° ThicknessofCr-coatingLayer:0.03-0.08mm DepthofBimetallicLayer:>2mm