Twin screwsMAXI MELT can supply a complete range of twin screws, cylindrical and conical. Based on our large experience we can recommend the proper type of steel and surface treatment to minimize wear. According to customer’s needs we can propose nitriding steel with welding and plasma on flights top.

We deliver screws according to OEM’s design that match the original geometry. But we can also deliver screws with a proprietary design developed by our engineers. The development of proprietary design is based on deep polymer background and wide experience in polymer processing, which may also help you in the optimisation of your production. Up to date machinery and  CAD CAM facilities make possible to manufacture also screws with complex design over a large scale of products with tight tolerances and very fine surface finish.

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.

Counter rotation screwScrew coatings

Coating Thickness of layer (mm) Hardness Abrasion resistance Corrosion resistance
Chrome plating 0,020 – 0,035 800 – 1100 HV 0,1 xxxx xxx
Nickel 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 41CrAlMo7 Nitriding steel Nitrided 950 – 1100 HV5 x x
1.8550 34CrAINi7 Nitriding steel Nitrided 950 – 1100 HV5 x x
1.2379 X155CrVMo121 Tool steel Hardened 59 – 63 HRC xxx xx
KPM1 PM material Hardened 58 – 63 HRC xxxx xxx
KPM2 PM material Hardened 55 – 60 HRC xxx xxxxx
Suitability: (x good) to (xxxxx excellent). PM is powder material. Other materials avaiable on request.