Stainless Steel 403 vs 420C
Stainless Steel · grade comparison
Stainless Steel 403 and 420C are both stainless steel grades. 403 is the stronger of the two: yield strength 655 MPa (95 ksi) against 460 MPa (66.7 ksi) for 420C, about 42% more; tensile strength follows at 830 MPa (120 ksi) vs 760 MPa (110 ksi). 403 is the more ductile: elongation 20% versus 17% for 420C, and 403 is harder (262 HB vs 220 HB). 420C is stiffer (215 GPa vs 200 GPa) and 403 runs hotter in service (540°C vs 400°C continuous). On the shop floor, 403 welds better (fair vs poor).
403Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.
403 vs 420C: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all stainless 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 stainless 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.
Elastic (Young's) Modulus
Shear Modulus
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)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
Hardness, Vickers
Hardness, Rockwell B
Same in both: Bulk Modulus 160 GPa23.2 Msi
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)
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 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
Weldability
Formability (cold)
Castability
Polishability
Same in both: Machinability Rating (AISI 1212 = 100 %) 45% · Brazeability / Solderability 45 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
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 stainless steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Manufacturing and finishing
| Capability | 403 | 420C |
|---|---|---|
| Sheet metal | Yes | — |
| Default condition | Hardened & Tempered | — |
| Relative cost | $$$ Premium | $$$ Premium |
| Min. machined wall | 0.8 mm | 0.8 mm |
| Best machined surface | Ra 1.6 µm | Ra 1.6 µm |
Both are offered for CNC machining. Both take the same 32 finishes: AlCrN, AlTiN, Black Oxide, CVD Al2O3, CVD TiCN, CVD TiN, Cerakote, Chrome Plating, CrN, DLC, Electroless Nickel (EN), Electropolishing and 20 more.
403 vs 420C — frequently asked
Is 403 stronger than 420C?
Yes. 403 has a typical yield strength of 655 MPa (95 ksi) against 460 MPa (66.7 ksi) for 420C — about 42% more. Tensile strength is 830 MPa (120 ksi) vs 760 MPa (110 ksi).
Which is cheaper, 403 or 420C?
Both sit in the same relative cost tier ($$$, premium); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which welds better, 403 or 420C?
403. Its weldability rates fair (35/100) against poor (20/100) for 420C.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 403 and 420C 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.