Stainless Steel 13-8 PH vs 420J1
Stainless Steel · grade comparison
Stainless Steel 13-8 PH and 420J1 are both stainless steel grades, both high strength ss. 13-8 PH is the stronger of the two: yield strength 827 MPa (120 ksi) against 440 MPa (63.8 ksi) for 420J1, about 88% more; tensile strength follows at 1,000 MPa (145 ksi) vs 700 MPa (102 ksi). In exchange, 420J1 is the more ductile: elongation 22% versus 13% for 13-8 PH, and 13-8 PH is harder (311 HB vs 195 HB). 420J1 runs hotter in service (600°C vs 425°C continuous) and 420J1 conducts heat better (30 W/m·K vs 14 W/m·K). On the shop floor, 420J1 machines more easily (fair vs poor), 13-8 PH welds better (good vs fair), and 420J1 sits in a lower cost tier (premium, $$$) than 13-8 PH (specialty, $$$$$).
13-8 PHChoose it when strength drives the design, or when it will be welded.
420J1Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
13-8 PH vs 420J1: 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.
Bulk Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
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: Elastic (Young's) Modulus 200 GPa29 Msi · Shear Modulus 78 GPa11.3 Msi · Reduction in Area 55%
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)
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 270 J/g116 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 %)
Weldability
Formability (cold)
Castability
Brazeability / Solderability
Same in both: Polishability 80 / 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 | 13-8 PH | 420J1 |
|---|---|---|
| Sheet metal | Yes | — |
| Default condition | Condition A | Annealed |
| Relative cost | $$$$$ Specialty | $$$ 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.
13-8 PH vs 420J1 — frequently asked
Is 13-8 PH stronger than 420J1?
Yes. 13-8 PH has a typical yield strength of 827 MPa (120 ksi) against 440 MPa (63.8 ksi) for 420J1 — about 88% more. Tensile strength is 1,000 MPa (145 ksi) vs 700 MPa (102 ksi).
Which is cheaper, 13-8 PH or 420J1?
420J1 is the lower-cost material: it sits in the premium tier ($$$) while 13-8 PH is specialty ($$$$$). 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, 13-8 PH or 420J1?
420J1. Its machinability rates fair (48/100) against poor (32/100) for 13-8 PH; for welding the order is 13-8 PH first (good, 62/100) then 420J1 (fair, 35/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 13-8 PH and 420J1 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.