Steel H21 vs H42
Steel · grade comparison
Steel H21 and H42 are both steel grades. H21 is the stronger of the two: yield strength 620 MPa (89.9 ksi) against 550 MPa (79.8 ksi) for H42, about 13% more; tensile strength follows at 900 MPa (131 ksi) vs 830 MPa (120 ksi). H21 is the more ductile: elongation 18% versus 16% for H42. H21 runs hotter in service (450°C vs 400°C continuous). On the shop floor, H21 welds better (fair vs poor) and H21 sits in a lower cost tier (standard, $$) than H42 (high, $$$$).
H21Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.
H21 vs H42: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Bulk Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Hardness, Brinell
Hardness, Rockwell C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 81 GPa11.7 Msi · Poisson's Ratio 0.29 · Charpy V-Notch Impact (RT) 25 J18.4 ft·lbf · Hardness, Rockwell B 97 HRB
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Liquidus Temperature
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -20°C-4 °F
Electrical
Conductivity and insulation.
Electrical Resistivity
Same in both: Electrical Conductivity 3.1 % IACS
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Galvanic Potential (seawater, vs SCE)
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Castability
Same in both: Brazeability / Solderability 40 / 100 · Polishability 65 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
Same in both: Embodied Energy (primary production) 42 MJ/kg18,057 BTU/lb
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
Strength versus weight
Yield strength against density for every steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Manufacturing and finishing
| Capability | H21 | H42 |
|---|---|---|
| CNC machining | Yes | — |
| Default condition | Annealed | — |
| Relative cost | $$ Standard | $$$$ High |
| Min. machined wall | 0.8 mm | — |
| Best machined surface | Ra 1.6 µm | — |
| AlCrN | Yes | — |
| AlTiN | Yes | — |
| Black Oxide | Yes | — |
| CVD Al2O3 | Yes | — |
| CVD TiCN | Yes | — |
| CVD TiN | Yes | — |
| Cerakote | Yes | — |
| Chrome Plating | Yes | — |
| CrN | Yes | — |
| DLC | Yes | — |
| E-Coating | Yes | — |
| HVOF Coating | Yes | — |
| Hot-Dip Galvanizing | Yes | — |
| MoS2 | Yes | — |
| Multilayer CVD | Yes | — |
| Nickel Plating | Yes | — |
| PTFE Coating | Yes | — |
| Painting | Yes | — |
They share 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.
H21 vs H42 — frequently asked
Is H21 stronger than H42?
Yes. H21 has a typical yield strength of 620 MPa (89.9 ksi) against 550 MPa (79.8 ksi) for H42 — about 13% more. Tensile strength is 900 MPa (131 ksi) vs 830 MPa (120 ksi).
Which is cheaper, H21 or H42?
H21 is the lower-cost material: it sits in the standard tier ($$) while H42 is high ($$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
Which is easier to machine, H21 or H42?
H21. Its machinability rates fair (40/100) against poor (32/100) for H42; for welding the order is H21 first (fair, 35/100) then H42 (poor, 25/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in H21 and H42 side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.
Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.