What is Harder (stiffer) Cast Magnesium or Cast Alum

Dear Forum Readers,

Which is harder (stiffer) that resists flexing, Cast aluminum or cast magnesium? Thank you for your time.

Craig D.
cde744@aol.com

 

[metman]

Stiffness or resistance to flexing is a function of modulus-of-elasticity (usually represented as E).

E for Aluminum is 9 million psi
E for Magnesiun is 6.35 million psi

Aluminum is stiffer. The numbers above are for the pure or elemental metal in both cases. Aluminum ALLOYS are actually approximately 10% stiffer than pure Aluminum. In other words about 10 million psi.

Don't confuse hardness with stiffness. Hardness is relative to strength. Strength and stiffness are two different characteristics of metals.