SK600 series are based on SK300 alloy steel which are imported from Japan, through vacuum quenching treatment, the screw surface use the American Stellite and German Castolin Fe-based,Nickel based, cobalt-based tungsten carbide supersonic radiation technology to make the screw working part covered by alloy, depth 1-2mm, bonding strengh approximate 210bar, hardness 60-65HRC. Super function of anti wear and corrosion. Alloy composition: C:2.3, Cr:26,Mo:5.2, Si:1, W:18,Mn:1.2,Ni:0.3,V:8,Co:6

Perfect wear and corrosion resistance fit for halgo free engineering plastic+lower than 65%GF in high wear and corrosion environment.But it is very strict for production environment,working procedure and disassemble. (we do not recommend it unless special requirment.