ASTM A387 Grade 21 Steel vs. ASTM Grade HN Steel
Both ASTM A387 grade 21 steel and ASTM grade HN steel are iron alloys. They have 55% of their average alloy composition in common. There are 25 material properties with values for both materials. Properties with values for just one material (8, in this case) are not shown.
For each property being compared, the top bar is ASTM A387 grade 21 steel and the bottom bar is ASTM grade HN steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 150 to 180 | |
| 140 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 200 |
| Elongation at Break, % | 21 | |
| 9.0 |
| Poisson's Ratio | 0.29 | |
| 0.28 |
| Shear Modulus, GPa | 74 | |
| 77 |
| Tensile Strength: Ultimate (UTS), MPa | 500 to 590 | |
| 500 |
Thermal Properties
| Latent Heat of Fusion, J/g | 260 | |
| 310 |
| Maximum Temperature: Mechanical, °C | 480 | |
| 1080 |
| Melting Completion (Liquidus), °C | 1470 | |
| 1400 |
| Melting Onset (Solidus), °C | 1430 | |
| 1350 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 480 |
| Thermal Conductivity, W/m-K | 41 | |
| 13 |
| Thermal Expansion, µm/m-K | 13 | |
| 16 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 4.1 | |
| 26 |
| Density, g/cm3 | 7.9 | |
| 7.9 |
| Embodied Carbon, kg CO2/kg material | 1.8 | |
| 4.6 |
| Embodied Energy, MJ/kg | 23 | |
| 66 |
| Embodied Water, L/kg | 62 | |
| 180 |
Common Calculations
| PREN (Pitting Resistance) | 6.4 | |
| 22 |
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 24 | |
| 25 |
| Strength to Weight: Axial, points | 18 to 21 | |
| 17 |
| Strength to Weight: Bending, points | 18 to 20 | |
| 18 |
| Thermal Diffusivity, mm2/s | 11 | |
| 3.5 |
| Thermal Shock Resistance, points | 14 to 17 | |
| 11 |
Alloy Composition
| Carbon (C), % | 0.050 to 0.15 | |
| 0.2 to 0.5 |
| Chromium (Cr), % | 2.8 to 3.3 | |
| 19 to 23 |
| Iron (Fe), % | 94.4 to 96 | |
| 44.9 to 57.8 |
| Manganese (Mn), % | 0.3 to 0.6 | |
| 0 to 2.0 |
| Molybdenum (Mo), % | 0.9 to 1.1 | |
| 0 to 0.5 |
| Nickel (Ni), % | 0 | |
| 23 to 27 |
| Phosphorus (P), % | 0 to 0.025 | |
| 0 to 0.040 |
| Silicon (Si), % | 0 to 0.5 | |
| 0 to 2.0 |
| Sulfur (S), % | 0 to 0.025 | |
| 0 to 0.040 |