Steel Fe-Co 50 (unalloyed) vs Permendur
Steel · grade comparison
Steel Fe-Co 50 (unalloyed) and Permendur are both steel grades. Fe-Co 50 (unalloyed) is the stronger of the two: yield strength 800 MPa (116 ksi) against 340 MPa (49.3 ksi) for Permendur, about 135% more; tensile strength follows at 900 MPa (131 ksi) vs 520 MPa (75.4 ksi). In exchange, Permendur is the more ductile: elongation 3% versus 1.5% for Fe-Co 50 (unalloyed), and Fe-Co 50 (unalloyed) is harder (300 HB vs 190 HB). Permendur runs hotter in service (500°C vs 400°C continuous) and Fe-Co 50 (unalloyed) conducts heat better (43 W/m·K vs 29.8 W/m·K). On the shop floor, Permendur welds better (fair vs poor).
Fe-Co 50 (unalloyed)Choose it when strength drives the design.
PermendurChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
Fe-Co 50 (unalloyed) vs Permendur: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all 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 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
Bulk 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
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 420 J/kg·K0.1 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
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Polishability
Same in both: Castability 30 / 100 · Brazeability / Solderability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: Typical Recycled Content 25%
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 steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Manufacturing and finishing
| Capability | Fe-Co 50 (unalloyed) | Permendur |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Both take the same 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.
Fe-Co 50 (unalloyed) vs Permendur — frequently asked
Is Fe-Co 50 (unalloyed) stronger than Permendur?
Yes. Fe-Co 50 (unalloyed) has a typical yield strength of 800 MPa (116 ksi) against 340 MPa (49.3 ksi) for Permendur — about 135% more. Tensile strength is 900 MPa (131 ksi) vs 520 MPa (75.4 ksi).
Which is cheaper, Fe-Co 50 (unalloyed) or Permendur?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which welds better, Fe-Co 50 (unalloyed) or Permendur?
Permendur. Its weldability rates fair (40/100) against poor (20/100) for Fe-Co 50 (unalloyed).
Ready to make it?
Upload a CAD file and FabDigit prices the part in Fe-Co 50 (unalloyed) and Permendur 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.