Magnesium QH21A-T6 Alloy (UNS M18211)

Topics Covered

Chemical Composition
Physical Properties
Mechanical Properties
Thermal Properties


Magnesium is a silvery-white metal used as an alloy element for aluminum, lead, zinc and other nonferrous alloys. Magnesium QH21A-T6 alloy is pressure tight, and has good castability, high yield strength up to 250°C and good creep resistance.

The following datasheet gives an overview of magnesium QH21A-T6 alloy.

Chemical Composition

The following table shows the chemical composition of magnesium QH21A-T6 alloy.

Element Content (%)
Magnesium, Mg 95
Silver, Ag 2-3
Neodymium, Nd 0.60 - 1.5
Thorium, Th 0.60 - 1.6
Zirconium, Zr 0.40-1
Zinc, Zn ≤0.20
Copper, Cu ≤0.10
Nickel, Ni ≤0.010

Physical Properties

The physical properties of magnesium QH21A-T6 alloy are given in the following table.

Properties Metric Imperial
Density 1.83 g/cm³ 0.0661 lb/in³
Melting point 535-640°C 995-1180°F

Mechanical Properties

The mechanical properties of cast magnesium QH21A-T6 alloy are listed in the following table.

Properties Metric Imperial
Tensile strength 275 MPa 39900 psi
Yield strength (@ strain 0.200%) 2 MPa 29700 psi
Compressive yield strength 210 MPa 30500 psi
Fatigue strength (@# of cycles 5.00e+7) 105 MPa 15200 psi
Shear modulus 17 GPa 2470 ksi
Elastic modulus 45 GPa 6530 ksi
Poisson's ratio 0.32 0.32
Elongation at break (in 50 mm) 4% 4%
Machinability (relative rating, 100=best) 100 100

Thermal Properties

The following table outlines the thermal properties of magnesium QH21A-T6 alloy.

Properties Metric Imperial
Thermal expansion co-efficient (@ 0.000-100°C/32-212°F) 26.7 µm/m°C 14.8 µin/in°F
Thermal conductivity 113 W/mK 784 BTU in/hr.ft².°F


  1. Kim Yu Kim Yu Hong Kong S.A.R. says:

    Could we use this material for Die Casting?

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