Cast plate Castal Premium 70 EN AW 7020

Cast plate
EN AW 7021

Alcast is a 7021 T6 alloy that offers an excellent combination of superb mechanical properties and reduced residual stress.

Thanks to its high mechanical strength, excellent gloss, and dimensional stability during use and processing, Alcast is suitable for creating moulds for plastic materials, models, special technical moulds and structures for hydraulic applications, and various other types of general mechanical processing operations.

The casting technology and the high percentage of pure metal guarantee minimal porosity throughout the entire cross-section of the plate.

Alcast is particularly recommended for the following applications:

  • Resin transfer moulding;
  • Compression moulding;
  • Resin injection moulding;
  • Blow moulding;
  • Thermoforming.

Alcast is not recommended for moulds with complex shapes and sharp corners. For these applications, we recommend using rolled products wherever possible.

technical characteristics


  • TIG/DC: good for repairs
  • Wire: AA 5183

Surface treatments

  • Hard anodisation: good
  • Chrome plating: good
  • Suitability for polishing: optimal
  • Photoengraving suitable (studio Standex Italia-Baratè)


Alcast offers high workability, which is favoured by formal stability and fine grain shavings, excellent heat transfer capabilities and possibility of high speed machining.


Resistance to corrosion

  • Normal atmospheres: good


Alcast is available in the following formats:

  • Maximum thickness: 600 mm
  • Dimensions: 1520x4000 mm or 2000x4000

Other thicknesses and formats are available upon request.

General information

Chemical Composition (%weight)


Alcast is alloy 7021 T6 (EN 7020), which has zinc, magnesium and copper as its main alloying elements.

Physical properties (indicative values)

1 MPa = 1 N/mm2 = 0.10197 kg/mm2

  • Specific weight: 2.78 g/cm3
  • Elastic modulus 72000 MPa
  • Thermal conductivity: 150 W/m•K
  • Electrical conductivity (T=20°C): 19-23•106 S/m
  • Thermal linear expansion coefficient: (20°-100°C): 23.6·10-6 K-1

mechanical properties

Values measured at ¼ of the thickness

Minimum values (state H0)

Thickness (from…to) [mm]Rm [MPa]Rp0.2 [MPa]A50 [%]
150 - 6003102801.5

Typical mechanical values for different thicknesses

Thickness (from…to) [mm]Rm [MPa]Rp0.2 [MPa]A50 [%]HB
150 - 4003453203.0135
401 - 6003253002.5130

Alcast has uniform characteristics from the core to the surface.


Custom cuts can be made using a belt or circular saw upon request:

  • Creation of specially designed plates;
  • Creation of special profiles using water cutting technology;
  • Rotating circular saw cutting and finishing up to 2000 mm;
  • Milling on 1 or 2 sides;
  • Custom thicknesses;
  • Ring and flange cutting;
  • Precision cutting and trimming up to 250 mm.