MAXI MELT offers a full range of single and twin screws. Based on our extensive experience we offer different materials types and treatments to fight wear. The materials range from nitriding steels, stainless steels, tool steels up to steels produced by powder technology (PM).

Welding on screw flights

NameBase alloyAlloy componentsHardness (hrc)Abrasion resistanceCorrosion resistance
Stellite 1CobaltC, Cr, W52 – 57xxxxxx
Stellite 12CobaltC, Cr, W44 – 48xxxxx
Colmonoy 57NickelC, Si, Cr, B, Fe52 – 56xxxxxxx
Colmonoy 83NickelTungsten carbide56 – 60 (x)xxxxxxxxx
CastoTIG5IronCr, V58 – 62xxxxxx
Suitability: (x good) to (xxxxx excellent). (x) Tungsten carbides have a hardness of 89 HRC. Other materials on request.

The modification of the screw geometry can improve the plasticizing process and, also, can increase its durability. The MAXI MELT screw profile offers a lower compression ratio against a standard 3 zone screw and therefore also will offer a longer life than a standard 3 zone profile.

Screw coatings

CoatingThickness of layer (mm)HardnessAbrasion resistanceCorrosion resistance
Chrome plating0,020 – 0,035800 – 1100 HV 0,1xxxxxxx
Nikel plating0,015 – 0,025500 – 600 HV 0,1xxxxxxx
PVD, TiN0,0042500 HV 0,5xxxxx
PVD, CrN0,0042100 HV 0,5xxxxxx
PVD, CrN-multi layer0,0082100 HV 0,5xxxxxxxx
Suitability: (x good) to (xxxxx excellent)

Base materials for plastizing screws

DIN standardMaterialType steelTreatmentHardnessAbrasion resistanceCorrosion resistance
1.850941CrAIMo7Nitriding steelNitrided950 – 1150 HV 5xx
1.855034CrAINi7Nitriding steelNitrided950 – 1150 HV 5xx
1.4122X35CrMo17Nitriding steelNitrided1000 – 1100 HV5xxxx
1.2379X155CrVMo121Tool steelHardened59 – 63 HRCxxxxx
–KPM1PM materialHardened58 – 63 HRCxxxxxxx
–KPM2PM materialHardened55 – 62 HRCxxxxxxx
Suitability: (x good) to (xxxxx excellent). PM is powder material. Other materials on request.