0.5sourcegovernment (NBS J. Res. 68A, 1964): computed by NBS for peroxide-cured gum NR vulcanizate, 25 °C, infinitesimal deformation0.49 in the solver: the linear element locks as the ratio nears 0.5 (nearly incompressible).
0.32sourceMIL-HDBK-5J design value (AISI 4340, quenched and tempered)
Shear modulus
not sourced
75.7GPa
Bulk modulus
not sourced
185GPa
Speed of sound
not sourced
5,049m/s
Thermal
Thermal conductivity
0.151W/m·Ksourcegovernment selected value (US Army Natick Laboratories TR 66-49-PR, 1966), soft vulcanized natural rubber, 25 °C
Every value links to the document that states it. "Not sourced" means no citable source states it (or only a specification minimum); figures computed from it are left out too.
Questions
Is Rubber stronger than Steel AISI 4340?
Steel AISI 4340 is stronger: its yield strength is 1,035 MPa against tensile strength 23 MPa for Rubber (45x).
Which is lighter, Rubber or Steel AISI 4340?
Rubber is lighter: 960 kg/m³ against 7,840 kg/m³ for Steel AISI 4340.
Which is lighter for the same job, Rubber or Steel AISI 4340?
For the same stiffness or strength: Rubber is lighter for a strong panel or plate; Steel AISI 4340 is lighter for a strong rod or tie, strong beam.
Part that must be
Rubber
Steel AISI 4340
Strong rod or tie
5.51x heavier
lighter
Strong beam
1.55x heavier
lighter
Strong panel or plate
lighter
22% heavier
For the same stiffness or strength, mass scales with density over stiffness (or strength) raised to a power set by how the part is loaded: 1 for a rod in tension, 1/2 for a beam in bending, 1/3 for a panel (the standard material-selection indices).
Which conducts heat better, Rubber or Steel AISI 4340?
Steel AISI 4340 conducts heat better: 37.5 W/m·K against 0.151 W/m·K for Rubber.