Stainless Steel 420 vs 420J2
Stainless Steel · grade comparison
Stainless Steel 420 and 420J2 are both stainless steel grades, both high strength ss. 420J2 is the stronger of the two: yield strength 400 MPa (58 ksi) against 360 MPa (52.2 ksi) for 420, about 11% more. 420J2 is harder — 220 HB against 200 HB for 420 — which matters for wear surfaces and threads.
420J2Choose it when strength drives the design, or when surface hardness matters.
420 vs 420J2: 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.
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 B
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 200 GPa29 Msi · Shear Modulus 78 GPa11.3 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29
Physical
Density and transition temperatures.
Melting Point (Solidus)
Same in both: Density 7.75 g/cm³0.28 lb/in³ · Liquidus Temperature 1,510°C2,750 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Expansion (CTE, 20–100 °C)
Same in both: Thermal Conductivity 24.9 W/m·K14.4 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Latent Heat of Fusion 260 J/g112 BTU/lb · Max Service Temperature (continuous) 650°C1,202 °F · Min Service Temperature -30°C-22 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 3.1 % IACS · Electrical Resistivity 5.5×10⁻⁷ Ω·m21.7 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Galvanic Potential (seawater, vs SCE)
Same in both: Corrosion Resistance 40 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Castability
Same in both: Machinability Rating (AISI 1212 = 100 %) 45% · Weldability 25 / 100 · Formability (cold) 40 / 100 · Brazeability / Solderability 40 / 100 · Polishability 85 / 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)
Modulus of Resilience
Same in both: Specific Stiffness (E / density) 25.8 MN·m/kg · Thermal Diffusivity 7 mm²/s · Thermal Shock Resistance Index 8
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 | 420 | 420J2 |
|---|---|---|
| Default condition | Annealed | Annealed |
| 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.
420 vs 420J2 — frequently asked
Is 420J2 stronger than 420?
Yes. 420J2 has a typical yield strength of 400 MPa (58 ksi) against 360 MPa (52.2 ksi) for 420 — about 11% more. Tensile strength is 700 MPa (102 ksi) vs 690 MPa (100 ksi).
Which is cheaper, 420 or 420J2?
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.
When should I choose 420 over 420J2?
Pick 420J2 when strength drives the design, or when surface hardness matters.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 420 and 420J2 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.