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K1A (K1A-F, M18010) Magnesium

K1A magnesium is a magnesium alloy. It is typically furnished in the as-fabricated (no temper or treatment) condition. K1A is the ASTM designation for this material. M18010 is the UNS number. It has the lowest density among magnesium alloys. In addition, it has the highest ductility and the highest melting temperature. The graph bars on the material properties cards below compare K1A magnesium to other magnesium alloys (top) and the entire database (bottom).

Mechanical Properties

Elastic (Young's, Tensile) Modulus

43 GPa 6.3 x 106 psi

Elongation at Break

13 %

Fatigue Strength

39 MPa 5.6 x 103 psi

Poisson's Ratio


Shear Modulus

17 GPa 2.4 x 106 psi

Shear Strength

55 MPa 8.0 x 103 psi

Tensile Strength: Ultimate (UTS)

180 MPa 26 x 103 psi

Tensile Strength: Yield (Proof)

51 MPa 7.4 x 103 psi

Thermal Properties

Melting Completion (Liquidus)

650 °C 1210 °F

Melting Onset (Solidus)

650 °C 1200 °F

Solidification (Pattern Maker's) Shrinkage

1.6 %

Specific Heat Capacity

1000 J/kg-K 0.24 BTU/lb-°F

Thermal Conductivity

120 W/m-K 69 BTU/h-ft-°F

Thermal Expansion

27 µm/m-K

Electrical Properties

Electrical Conductivity: Equal Volume

30 % IACS

Electrical Conductivity: Equal Weight (Specific)

170 % IACS

Otherwise Unclassified Properties

Base Metal Price

13 % relative


1.6 g/cm3 100 lb/ft3

Embodied Carbon

24 kg CO2/kg material

Embodied Energy

170 MJ/kg 72 x 103 BTU/lb

Embodied Water

970 L/kg 120 gal/lb

Common Calculations

Resilience: Ultimate (Unit Rupture Work)

17 MJ/m3

Resilience: Unit (Modulus of Resilience)

30 kJ/m3

Stiffness to Weight: Axial

15 points

Stiffness to Weight: Bending

73 points

Strength to Weight: Axial

31 points

Strength to Weight: Bending

43 points

Thermal Diffusivity

75 m2/s

Thermal Shock Resistance

11 points

Alloy Composition

Magnesium (Mg) 98.7 to 99.6
Zirconium (Zr) 0.4 to 1.0
Residuals 0 to 0.3

All values are % weight. Ranges represent what is permitted under applicable standards.

Followup Questions

Similar Alloys

Further Reading

ASTM B80: Standard Specification for Magnesium-Alloy Sand Castings

ASTM B403: Standard Specification for Magnesium-Alloy Investment Castings

Environmental Degradation of Advanced and Traditional Engineering Materials, Lloyd H. Hihara et al., 2014.

Welding and Joining of Magnesium Alloys, Liming Liu ed., 2010

Properties and Selection: Nonferrous Alloys and Special-Purpose Materials, ASM Handbook vol. 2, ASM International, 1993