ASTM Grade HK Steel vs. ASTM A231 Spring Steel
Both ASTM grade HK steel and ASTM A231 spring steel are iron alloys. They have 54% of their average alloy composition in common. There are 29 material properties with values for both materials. Properties with values for just one material (5, in this case) are not shown.
For each property being compared, the top bar is ASTM grade HK steel and the bottom bar is ASTM A231 spring steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 150 | |
| 540 |
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 190 |
| Elongation at Break, % | 11 | |
| 14 |
| Fatigue Strength, MPa | 150 | |
| 1000 |
| Poisson's Ratio | 0.27 | |
| 0.29 |
| Shear Modulus, GPa | 79 | |
| 73 |
| Tensile Strength: Ultimate (UTS), MPa | 500 | |
| 1790 |
| Tensile Strength: Yield (Proof), MPa | 270 | |
| 1570 |
Thermal Properties
| Latent Heat of Fusion, J/g | 310 | |
| 250 |
| Maximum Temperature: Mechanical, °C | 1100 | |
| 420 |
| Melting Completion (Liquidus), °C | 1400 | |
| 1460 |
| Melting Onset (Solidus), °C | 1350 | |
| 1410 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 470 |
| Thermal Conductivity, W/m-K | 15 | |
| 52 |
| Thermal Expansion, µm/m-K | 17 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 2.0 | |
| 7.3 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 2.3 | |
| 8.4 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 25 | |
| 2.3 |
| Density, g/cm3 | 7.8 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 4.4 | |
| 2.0 |
| Embodied Energy, MJ/kg | 63 | |
| 28 |
| Embodied Water, L/kg | 200 | |
| 51 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 48 | |
| 230 |
| Stiffness to Weight: Axial, points | 14 | |
| 13 |
| Stiffness to Weight: Bending, points | 25 | |
| 24 |
| Strength to Weight: Axial, points | 18 | |
| 64 |
| Strength to Weight: Bending, points | 18 | |
| 42 |
| Thermal Diffusivity, mm2/s | 3.9 | |
| 14 |
| Thermal Shock Resistance, points | 11 | |
| 53 |
Alloy Composition
| Carbon (C), % | 0.2 to 0.6 | |
| 0.48 to 0.53 |
| Chromium (Cr), % | 24 to 28 | |
| 0.8 to 1.1 |
| Iron (Fe), % | 44.8 to 57.8 | |
| 96.7 to 97.7 |
| Manganese (Mn), % | 0 to 2.0 | |
| 0.7 to 0.9 |
| Molybdenum (Mo), % | 0 to 0.5 | |
| 0 |
| Nickel (Ni), % | 18 to 22 | |
| 0 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 to 0.040 |
| Silicon (Si), % | 0 to 2.0 | |
| 0.15 to 0.35 |
| Sulfur (S), % | 0 to 0.040 | |
| 0 to 0.040 |
| Vanadium (V), % | 0 | |
| 0.15 to 0.3 |