Stainless Steel 40Kh13 vs 420
Stainless Steel · grade comparison
Stainless Steel 40Kh13 and 420 are both stainless steel grades. 40Kh13 is the stronger of the two: yield strength 420 MPa (60.9 ksi) against 360 MPa (52.2 ksi) for 420, about 17% more. 40Kh13 is stiffer (215 GPa vs 200 GPa) and 420 runs hotter in service (650°C vs 550°C continuous). On the shop floor, 40Kh13 sits in a lower cost tier (standard, $$) than 420 (premium, $$$).
40Kh13Choose it when strength drives the design, or when cost is the deciding factor.
420Choose it when the part sees heat.
40Kh13 vs 420: 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)
Charpy V-Notch Impact (RT)
Hardness, Rockwell B
Same in both: Bulk Modulus 160 GPa23.2 Msi · Fracture Toughness (K_IC) 60 MPa·√m54.6 ksi·√in · Hardness, Brinell 200 HB · Hardness, Vickers 210 HV
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).
Same in both: Galvanic Potential (seawater, vs SCE) -0.3 V · Corrosion Resistance 40 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Castability
Brazeability / Solderability
Polishability
Same in both: Machinability 45 / 100 · Machinability Rating (AISI 1212 = 100 %) 45% · Weldability 25 / 100 · Formability (cold) 40 / 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
Thermal Shock Resistance Index
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 | 40Kh13 | 420 |
|---|---|---|
| CNC machining | — | Yes |
| Default condition | — | Annealed |
| Relative cost | $$ Standard | $$$ Premium |
| 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 |
| Electropolishing | — | Yes |
| HVOF Coating | — | Yes |
| MoS2 | — | Yes |
| Multilayer CVD | — | Yes |
| Nickel Plating | — | Yes |
| PTFE Coating | — | Yes |
| Painting | — | Yes |
| Passivation (Stainless Steel) | — | Yes |
They share 7 finishes: Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Pickling, Plasma Spray, Silver Plating.
40Kh13 vs 420 — frequently asked
Is 40Kh13 stronger than 420?
Yes. 40Kh13 has a typical yield strength of 420 MPa (60.9 ksi) against 360 MPa (52.2 ksi) for 420 — about 17% more. Tensile strength is 700 MPa (102 ksi) vs 690 MPa (100 ksi).
Which is cheaper, 40Kh13 or 420?
40Kh13 is the lower-cost material: it sits in the standard tier ($$) while 420 is premium ($$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
When should I choose 40Kh13 over 420?
Pick 40Kh13 when strength drives the design, or when cost is the deciding factor. Pick 420 when the part sees heat.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 40Kh13 and 420 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.