Spring Material Elastic Modulus Reference

Young modulus and shear modulus

Spring calculations use elastic constants that describe different deformation modes. Young’s modulus E relates normal stress to axial strain in the linear elastic range. Shear modulus G relates shear stress to shear strain. The table reports both for selected wire materials in millions of pounds per square inch. They are not interchangeable: a helical spring’s response depends on the load mode and geometry, so use the constant required by the governing spring equation.

The manufacturer lists E = 30 million psi and G = 11.5 million psi for several high-carbon and alloy spring wires. It lists different values for stainless grades, including E = 28 and G = 10 for 302/304 and 316, and E = 29.5 and G = 11 for 17-7 PH. This variation matters when deflection or rate is calculated; a single generic steel modulus may not match every material entry.

Keep wire grade and condition attached

The material names in the source describe spring-wire product categories, not every heat, diameter or processing condition. Music wire and hard-drawn MB are high-carbon wire; oil-tempered chrome silicon and chrome vanadium are alloy spring wires. Stainless 17-7 PH is precipitation hardened after spring fabrication according to the guide. Confirm the purchasing specification, wire condition and supplier certificate before using a table value in a design calculation.

The guide also gives nominal chemistry and tensile-strength ranges. Those values have their own conditions and should not be flattened into a single representative strength. This reference focuses on modulus and the source’s maximum operating-temperature guidance. It does not provide a complete spring-design allowable, fatigue limit or stress correction for coil geometry.

Temperature guidance is a separate field

Maximum operating temperature is a manufacturer selection guide value. It is not a statement that E and G were measured at that temperature, nor does it establish creep, relaxation or fatigue behavior there. The source lists 250°F for selected high-carbon wires, 475°F for chrome silicon, 425°F for chrome vanadium, 550°F for 302/304 and 316, and 600°F for 17-7 PH. Verify the spring supplier’s current limit for the actual load and environment.

Temperature can change modulus and long-term load retention. Corrosion, stress amplitude, cycle count, wire size and residual stress can also influence spring performance. When a spring operates near the guide limit or under sustained load, request data for the intended condition rather than treating the table limit as a guaranteed design temperature.

Check calculations and units

Before calculating a spring rate, confirm that force, length and modulus units are consistent. If dimensions are in millimetres, convert modulus to a compatible stress unit or convert the geometry to inches. A unit mismatch can produce a result that is wrong by a large factor. Keep E and G clearly labeled in the calculation record and state whether the spring is loaded in compression, extension, torsion or another configuration.

For isotropic materials, E and G may be related through Poisson’s ratio by G = E/[2(1+ν)]. That relation should be used only with a compatible material assumption and consistent data; it is not a substitute for a source measurement or a spring-specific property. The guide gives E and G directly, so use the listed values as reported rather than back-calculating one from the other.

Limits of this material lookup

The source is a spring manufacturer’s selection guide, useful for comparing common wire materials. It does not certify a finished spring or replace the drawing, material specification, qualification test or design standard. Do not infer a safe load from modulus. Spring geometry, stress concentration, end condition, fatigue duty and installation affect load capacity and life. Use a qualified spring designer for safety-critical or high-cycle applications.

The data may be revised as supplier products change. Confirm current information with the wire or spring supplier, especially for precipitation-hardened and nickel-alloy grades. Retain the material designation, units and operating-temperature condition together with any calculated rate or deflection so a reviewer can reproduce the calculation and check the assumptions.

Source and scope

Source: Quick Spring, Spring Wire Materials & Selection Guide. Use the source edition and conditions stated in the table.