Materials / Compare
Silicon vs. Steel
Compare Silicon vs. Steel strength, stiffness, weight and thermal properties.
| Try it on a partA sample part to run stress or thermal on, free in your browser | Open in LessCAD | Open in LessCAD |
|---|---|---|
| Mechanical | ||
| Yield strength | not given (tensile used) | 385MPasourcetypical: mean of 20,295 A992 flange mill-test coupons (1998 SSPC survey), as reported by AISC |
| Ultimate tensile strength | 130MPasourcemodulus of rupture (bending fracture stress); brittle, no yield point | 505MPasourcetypical: mean of 20,295 A992 flange mill-test coupons (1998 SSPC survey) |
| Flexural strength | 130MPasourcemodulus of rupture | not sourced |
| Elongation at break | not sourced | not sourced |
| Young's modulus (stiffness) | 131GPasourcetypical (single quoted value of an anisotropic crystal) | 200GPasourcedesign value (AISC 360-16) |
| Density | 2,329kg/m³sourcetypical | 7,850kg/m³sourcenominal (constructional data) |
| Strength to weight | 55.8kN·m/kg14% higher | 49kN·m/kg |
| Stiffness to weight | 56.2MN·m/kg2.21x higher | 25.5MN·m/kg |
| Poisson's ratio | 0.221sourcetypical | 0.3sourcedesign value (AISC 360-16 Commentary) |
| Shear modulus | 53.6GPa | 76.9GPa43% stiffer in shear |
| Bulk modulus | 78.3GPa | 167GPa |
| Speed of sound | 7,500m/s | 5,048m/s |
| Thermal | ||
| Thermal conductivity | 163W/m·Ksourcetypical at 313 K (40 °C) | 48W/m·Ksourcenominal at 20 °C |
| Thermal expansion | 2.62µm/m·Ksourcetypical at 300 K | 12µm/m·Ksourcenominal (constructional data, no temperature range stated) |
| 100 mm part over a 50 °C swing | 13.1µm growth4.58x less | 60µm growth |
| Specific heat | 732J/kg·Ksourcetypical | 460–480J/kg·Ksourcebase material: EN S275JR unalloyed structural steel (the EN counterpart of A36), typical, 50/100 °C |
| Heats up and cools (diffusivity) | 95.6mm²/s7.35x faster | 13mm²/s |
| Thermal shock resistance | 48,095W/m8.92x more resistant | 5,390W/m |
| Melting point | 1,412°Csourcetypical | not sourced |
| Max service temperature | 300°Csourceproducer's maximum application temperature (optical components) | not sourced |
| Values for | Synthetic single-crystal silicon (cubic, diamond structure), Korth Kristalle (crystal grower) material data; Korth usually supplies Floating Zone (FZ) material, Czochralski (Cz) also offered. Silicon is elastically anisotropic; the producer quotes one modulus and the solver is isotropic. | Generic structural steel, cited as ASTM A992 (the current US structural grade): ASTM A992 W-shapes; Fy/Fu specified minimums from AISC publications (AISC 360-16 Commentary; Modern Steel Construction); elastic constants AISC 360; physical constants from the bauforumstahl structural-steel EPD, which names A992 among covered product standards. |
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 Silicon stronger than Steel?
Steel is stronger: its yield strength is 385 MPa against tensile strength 130 MPa for Silicon (2.96x).
Which is lighter, Silicon or Steel?
Silicon is lighter: 2,329 kg/m³ against 7,850 kg/m³ for Steel.
Which is stiffer, Silicon or Steel?
Steel is stiffer: Young's modulus 200 GPa against 131 GPa for Silicon, so the same part in Steel deflects less under the same load.
Which is lighter for the same job, Silicon or Steel?
For the same stiffness or strength: Silicon is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate, strong rod or tie, strong beam, strong panel or plate.
| Part that must be | Silicon | Steel |
|---|---|---|
| Stiff rod or tie (tension) | lighter | 2.21x heavier |
| Stiff beam (bending) | lighter | 2.73x heavier |
| Stiff panel or plate | lighter | 2.93x heavier |
| Strong rod or tie | lighter | 14% heavier |
| Strong beam | lighter | 1.63x heavier |
| Strong panel or plate | lighter | 1.96x 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, Silicon or Steel?
Silicon conducts heat better: 163 W/m·K against 48 W/m·K for Steel.
Which expands less with temperature?
Silicon expands less: 2.62 µm/m·K against 12 µm/m·K for Steel.