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

Name Base alloy Alloy components Hardness (hrc) Abrasion resistance Corrosion resistance
Stellite 1 Cobalt C, Cr, W 52 – 57 xxx xxx
Stellite 12 Cobalt C, Cr, W 44 – 48 xx xxx
Colmonoy 57 Nickel C, Si, Cr, B, Fe 52 – 56 xxx xxxx
Colmonoy 83 Nickel Tungsten carbide 56 – 60 (x) xxxxx xxxx
CastoTIG5 Iron Cr, V 58 – 62 xxxx xx
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

Coating Thickness of layer (mm) Hardness Abrasion resistance Corrosion resistance
Chrome plating 0,020 – 0,035 800 – 1100 HV 0,1 xxxx xxx
Nikel plating 0,015 – 0,025 500 – 600 HV 0,1 xx xxxxx
PVD, TiN 0,004 2500 HV 0,5 xxx xx
PVD, CrN 0,004 2100 HV 0,5 xxx xxx
PVD, CrN-multi layer 0,008 2100 HV 0,5 xxxx xxxx
Suitability: (x good) to (xxxxx excellent)

Base materials for plasticizing screws

DIN standard Material Type steel Treatment Hardness Abrasion resistance Corrosion resistance
1.8509 41CrAIMo7 Nitriding steel Nitrided 950 – 1150 HV 5 x x
1.8550 34CrAINi7 Nitriding steel Nitrided 950 – 1150 HV 5 x x
1.4122 X35CrMo17 Nitriding steel Nitrided 1000 – 1100 HV5 x xxx
1.2379 X155CrVMo121 Tool steel Hardened 59 – 63 HRC xxx xx
KPM1 PM material Hardened 58 – 63 HRC xxxxx xx
KPM2 PM material Hardened 55 – 62 HRC xxx xxxx
Suitability: (x good) to (xxxxx excellent). PM is powder material. Other materials on request.