ASTM A229 Spring Steel vs. ASTM A302 Alloy Steel
Both ASTM A229 spring steel and ASTM A302 alloy steel are iron alloys.
For each property being compared, the top bar is ASTM A229 spring steel and the bottom bar is ASTM A302 alloy steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 490 to 550 | |
| 180 to 190 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 190 |
| Elongation at Break, % | 14 | |
| 20 to 23 |
| Fatigue Strength, MPa | 710 to 790 | |
| 250 to 280 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 72 | |
| 73 |
| Shear Strength, MPa | 1020 to 1140 | |
| 370 to 390 |
| Tensile Strength: Ultimate (UTS), MPa | 1690 to 1890 | |
| 590 to 620 |
| Tensile Strength: Yield (Proof), MPa | 1100 to 1230 | |
| 350 to 390 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 250 |
| Maximum Temperature: Mechanical, °C | 400 | |
| 410 |
| Melting Completion (Liquidus), °C | 1450 | |
| 1460 |
| Melting Onset (Solidus), °C | 1410 | |
| 1420 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 470 |
| Thermal Conductivity, W/m-K | 50 | |
| 39 to 51 |
| Thermal Expansion, µm/m-K | 12 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.2 | |
| 7.2 to 7.4 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 8.3 | |
| 8.2 to 8.4 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 1.8 | |
| 2.4 to 3.0 |
| Density, g/cm3 | 7.8 | |
| 7.8 to 7.9 |
| Embodied Carbon, kg CO2/kg material | 1.4 | |
| 1.5 to 1.6 |
| Embodied Energy, MJ/kg | 19 | |
| 20 to 21 |
| Embodied Water, L/kg | 46 | |
| 48 to 50 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 200 to 230 | |
| 110 to 120 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 3260 to 4080 | |
| 330 to 410 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 24 | |
| 24 |
| Strength to Weight: Axial, points | 60 to 67 | |
| 21 to 22 |
| Strength to Weight: Bending, points | 40 to 43 | |
| 20 to 21 |
| Thermal Diffusivity, mm2/s | 14 | |
| 10 to 14 |
| Thermal Shock Resistance, points | 54 to 60 | |
| 17 to 18 |