Steel 5CrNiMo vs H21
Steel · grade comparison
Steel 5CrNiMo and H21 are both steel grades. H21 is the stronger of the two: yield strength 620 MPa (89.9 ksi) against 450 MPa (65.3 ksi) for 5CrNiMo, about 38% more; tensile strength follows at 900 MPa (131 ksi) vs 760 MPa (110 ksi). 5CrNiMo is lighter (7.83 g/cm³ vs 8.28 g/cm³ for H21) and H21 runs hotter in service (450°C vs 300°C continuous). On the shop floor, 5CrNiMo machines more easily (good vs fair).
5CrNiMoChoose it when weight is the constraint, or when the part is machined in volume.
H21Choose it when strength drives the design, or when the part sees heat.
5CrNiMo vs H21: 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.
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Reduction in Area
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Rockwell B
Hardness, Rockwell C
Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 81 GPa11.7 Msi · Bulk Modulus 160 GPa23.2 Msi · Elongation at Break 18% · Hardness, Brinell 220 HB · Hardness, Vickers 230 HV
Physical
Density and transition temperatures.
Density
Same in both: Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,480°C2,696 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Max Service Temperature (continuous)
Min Service Temperature
Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F
Electrical
Conductivity and insulation.
Electrical Resistivity
Electrical Conductivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Polishability
Castability
Brazeability / Solderability
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Typical Recycled Content
Same in both: Embodied Water 60 L/kg7.2 gal/lb
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Same in both: Thermal Shock Resistance Index 10
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 | 5CrNiMo | H21 |
|---|---|---|
| CNC machining | — | Yes |
| Default condition | — | Annealed |
| Relative cost | $$ Standard | $$ Standard |
| 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.
5CrNiMo vs H21 — frequently asked
Is H21 stronger than 5CrNiMo?
Yes. H21 has a typical yield strength of 620 MPa (89.9 ksi) against 450 MPa (65.3 ksi) for 5CrNiMo — about 38% more. Tensile strength is 900 MPa (131 ksi) vs 760 MPa (110 ksi).
Which is cheaper, 5CrNiMo or H21?
Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, 5CrNiMo or H21?
5CrNiMo. Its machinability rates good (55/100) against fair (40/100) for H21; for welding the order is H21 first (fair, 35/100) then 5CrNiMo (poor, 30/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 5CrNiMo and H21 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.