Modulus of Rigidity: Definition And Equation

Modulus of rigidity is the ratio of shear stress to the corresponding shear strain within the proportional limit of a material. Modulus of rigidity is also known as shear modulus and rigidity modulus values of materials are determined by torsional tests. Modulus of rigidity formulas are G = τ/γ and G = E/(2(1+v)). Here τ is shear stress, γ is shear strain in radians, G is modulus of rigidity, E is elastic modulus and v is Poisson’s ratio.

Shear modulus of steel, aluminum, iron, copper, titanium, brass, bronze, etc. are given in the following table in GPA and psi.

Modulus of Rigidity (Shear Modulus) of Materials
MaterialGPa106 psi
Aluminum263.8
Aluminum alloys, various25.5 – 26.93.7 – 3.9
Aluminum, 6061-T6263.8
Aluminum, 2024-T4284
Aluminum, 7075-T626.93.9
Beryllium copper (C17200)507.2
Brass, 70-30 (C26000)416
Yellow Brass (C27000)395.6
Red Brass (C23000)446.4
Aluminum Bronze (C95500)426.1
Manganese Bronze (C86350)375.4
Oxygen Free Copper (C10100)446.4
Glass Ceramic (Mica)263.7
Inconel X75079.311.5
Invar568.1
Iron8211.9
Iron, cast36-575.2-8.2
Iron, ductile63-669.1-9.6
Iron, gray cast (Class 20)27-393.9-5.7
Iron, malleable649.3
Lead5.60.8
Magnesium172.4
Magnesium alloy172.5
Molybdenum12017.4
Monel 40065.39.5 9.5
Nickel silver 55-18 (C77000)476.8
Nickel7611
Phosphor bronze (C51000)415.9
Steel, A3679.311.5
304 Stainless steel7711.2
Steel, cast7811.3
Steel, cold-rolled7911.5
Steel, all others including
high-carbon, heat-treated
76-8211.0-11.9
Titanium Grade 2 (99.0 Ti)456.5
Titanium Grade 5 (Ti-6Al-4V)446.4
Tungsten16023.2
Zinc436.2