Shear modulus table
Shear modulus (modulus of rigidity, G) for common materials, in millions of psi and gigapascals. It measures resistance to twisting and shearing, and sets how much a shaft winds up under torque or a part distorts under shear.
Shear modulus (G)
| Material | G (Mpsi) | G (GPa) |
|---|---|---|
| Steel (carbon and alloy) | 11.5 | 79 |
| Stainless steel | 11.2 | 77 |
| Nickel | 11 | 76 |
| Copper | 6.5 | 45 |
| Bronze | 6.5 | 45 |
| Titanium | 6.4 | 44 |
| Cast iron (gray) | 5.9 | 41 |
| Brass | 5.4 | 37 |
| Glass | 3.7 | 26 |
| Aluminum | 3.8 | 26 |
| Magnesium | 2.4 | 17 |
| Lead | 0.8 | 5.6 |
Shear modulus is linked to the elastic modulus and Poisson ratio by G = E / (2 (1 + v)). It is the key property for torsion: how far a shaft twists, how a spring deflects, and how much a part shears. For most metals G is roughly 38 to 40 percent of the Young modulus.
Need the elastic modulus or Poisson ratio?
See the Modulus of Elasticity Table and the Poisson Ratio Table.
Where shear modulus is used
Shear modulus governs anything that twists or shears rather than stretches. The angle a drive shaft winds up under torque, the deflection of a coil spring, and the rigidity of a torsion bar all depend on G. For a given torque, a higher G means less twist, so stiff shafts use high-modulus materials and generous diameters.
How G relates to E
For an isotropic material, the shear modulus follows directly from the Young modulus and Poisson ratio: G equals E divided by two times one plus the Poisson ratio. With a typical metal Poisson ratio near 0.3, that puts G at about 0.38 times E, which is why steel at 29 Mpsi has a shear modulus near 11.5 Mpsi.
FAQ
What is the shear modulus of steel?
About 11.5 million psi (79 GPa) for carbon and alloy steels.
How is shear modulus related to Young modulus?
By G = E / (2(1 + v)), where v is the Poisson ratio. For most metals G is roughly 38 percent of E.
What is shear modulus used for?
Torsion and shear problems: the twist of shafts, the deflection of springs, and the rigidity of parts loaded in shear rather than tension.