Stainless Steel 13-8 PH vs PH 13-8 Mo
Stainless Steel · grade comparison
Stainless Steel 13-8 PH and PH 13-8 Mo are both stainless steel grades, both high strength ss. Both yield at about 827 MPa — strength does not separate them. 13-8 PH runs hotter in service (425°C vs 315°C continuous). On the shop floor, PH 13-8 Mo forms better (fair vs poor) and PH 13-8 Mo sits in a lower cost tier (premium, $$$) than 13-8 PH (specialty, $$$$$).
13-8 PHChoose it when the part sees heat.
PH 13-8 MoChoose it when cost is the deciding factor.
13-8 PH vs PH 13-8 Mo: 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
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Vickers
Same in both: Shear Modulus 78 GPa11.3 Msi · Bulk Modulus 155 GPa22.5 Msi · Poisson's Ratio 0.28 · Tensile Strength (Ultimate) 1,000 MPa145 ksi · Fatigue Strength (Endurance Limit) 480 MPa69.6 ksi · Hardness, Rockwell C 33 HRC
Physical
Density and transition temperatures.
Same in both: Density 7.76 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,400°C2,552 °F · Liquidus Temperature 1,440°C2,624 °F
Thermal
How each material carries heat and how hot it can run.
Latent Heat of Fusion
Max Service Temperature (continuous)
Min Service Temperature
Same in both: Thermal Conductivity 14 W/m·K8.1 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 10.6 µm/m·K5.9 µin/in·°F
Electrical
Conductivity and insulation.
Electrical Resistivity
Same in both: Electrical Conductivity 1.7 % IACS
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.
Weldability
Formability (cold)
Castability
Brazeability / Solderability
Same in both: Machinability 32 / 100 · Machinability Rating (AISI 1212 = 100 %) 30% · Polishability 80 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Carbon (primary production)
Embodied Water
Same in both: Embodied Energy (primary production) 62 MJ/kg26,655 BTU/lb · Typical Recycled Content 30%
Common Calculations
Ratios derived from the values above.
Specific Stiffness (E / density)
Modulus of Resilience
Same in both: Specific Strength (UTS / density) 129 kN·m/kg · Thermal Diffusivity 3.9 mm²/s · Thermal Shock Resistance Index 7
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 | PH 13-8 Mo |
|---|---|---|
| Default condition | Condition A | Condition A |
| 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 and Sheet metal. 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 PH 13-8 Mo — frequently asked
What is the difference between 13-8 PH and PH 13-8 Mo?
Stainless Steel 13-8 PH and PH 13-8 Mo are both stainless steel grades, both high strength ss. Both yield at about 827 MPa — strength does not separate them. 13-8 PH runs hotter in service (425°C vs 315°C continuous).
Which is cheaper, 13-8 PH or PH 13-8 Mo?
PH 13-8 Mo 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.
When should I choose 13-8 PH over PH 13-8 Mo?
Pick 13-8 PH when the part sees heat. Pick PH 13-8 Mo when cost is the deciding factor.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 13-8 PH and PH 13-8 Mo 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.