Steel H13 vs H21
Steel · grade comparison
Steel H13 and H21 are both steel grades, both heat resistant steel. H21 is the stronger of the two: yield strength 620 MPa (89.9 ksi) against 520 MPa (75.4 ksi) for H13, about 19% more; tensile strength follows at 900 MPa (131 ksi) vs 760 MPa (110 ksi). In exchange, H13 is the more ductile: elongation 25% versus 18% for H21, and H21 is harder (220 HB vs 205 HB). H13 is lighter (7.8 g/cm³ vs 8.28 g/cm³ for H21) and H21 runs hotter in service (450°C vs 400°C continuous). On the shop floor, H21 sits in a lower cost tier (standard, $$) than H13 (high, $$$$).
H13Choose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
H21Choose it when strength drives the design, or when the part sees heat.
H13 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)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Fracture Toughness (K_IC)
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
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Same in both: 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)
Max Service Temperature (continuous)
Min Service Temperature
Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Latent Heat of Fusion 250 J/g107 BTU/lb
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Galvanic Potential (seawater, vs SCE)
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Brazeability / Solderability
Polishability
Castability
Same in both: Weldability 35 / 100 · Formability (cold) 20 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: Typical Recycled Content 45%
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 | H13 | H21 |
|---|---|---|
| 3D printing | Yes | — |
| Default condition | Annealed | Annealed |
| Relative cost | $$$$ High | $$ Standard |
| Min. machined wall | 0.8 mm | 0.8 mm |
| Best machined surface | Ra 1.6 µm | Ra 1.6 µm |
| Passivated (Metal AM) | Yes | — |
| Plated (Metal AM) | Yes | — |
Both are offered for CNC machining. They share 38 finishes: AlCrN, AlTiN, Black Oxide, CVD Al2O3, CVD TiCN, CVD TiN, Cerakote, Chrome Plating, Copper Plating, CrN, DLC, E-Coating and 26 more.
H13 vs H21 — frequently asked
Is H21 stronger than H13?
Yes. H21 has a typical yield strength of 620 MPa (89.9 ksi) against 520 MPa (75.4 ksi) for H13 — about 19% more. Tensile strength is 900 MPa (131 ksi) vs 760 MPa (110 ksi).
Which is cheaper, H13 or H21?
H21 is the lower-cost material: it sits in the standard tier ($$) while H13 is high ($$$$). 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, H13 or H21?
H13, by a small margin. Both rate fair for machinability — 45/100 against 40/100 for H21.
Ready to make it?
Upload a CAD file and FabDigit prices the part in H13 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.