Steel 45 Permalloy vs Fe-Co 50 (unalloyed)
Steel · grade comparison
Steel 45 Permalloy and Fe-Co 50 (unalloyed) are both steel grades. Fe-Co 50 (unalloyed) is the stronger of the two: yield strength 800 MPa (116 ksi) against 210 MPa (30.5 ksi) for 45 Permalloy, about 3.8 times as much; tensile strength follows at 900 MPa (131 ksi) vs 520 MPa (75.4 ksi). In exchange, 45 Permalloy is the more ductile: elongation 40% versus 1.5% for Fe-Co 50 (unalloyed), and Fe-Co 50 (unalloyed) is harder (300 HB vs 125 HB). Fe-Co 50 (unalloyed) is stiffer (210 GPa vs 152 GPa) and Fe-Co 50 (unalloyed) conducts heat better (43 W/m·K vs 13.5 W/m·K). On the shop floor, 45 Permalloy machines more easily (fair vs poor) and 45 Permalloy welds better (good vs poor).
45 PermalloyChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
Fe-Co 50 (unalloyed)Choose it when strength drives the design.
45 Permalloy vs Fe-Co 50 (unalloyed): 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.
45 PermalloyFe-Co 50 (unalloyed)
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Shear Modulus
Bulk Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Shear Strength
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Compressive Strength
Fracture Toughness (K_IC)
Hardness, Rockwell C
Same in both: Poisson's Ratio 0.3
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
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Min Service Temperature
Same in both: Max Service Temperature (continuous) 400°C752 °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)
Brazeability / Solderability
Polishability
Castability
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 steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Manufacturing and finishing
| Capability | 45 Permalloy | Fe-Co 50 (unalloyed) |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Both take the same 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.
45 Permalloy vs Fe-Co 50 (unalloyed) — frequently asked
Is Fe-Co 50 (unalloyed) stronger than 45 Permalloy?
Yes. Fe-Co 50 (unalloyed) has a typical yield strength of 800 MPa (116 ksi) against 210 MPa (30.5 ksi) for 45 Permalloy — about 3.8 times as much. Tensile strength is 900 MPa (131 ksi) vs 520 MPa (75.4 ksi).
Which is cheaper, 45 Permalloy or Fe-Co 50 (unalloyed)?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, 45 Permalloy or Fe-Co 50 (unalloyed)?
45 Permalloy. Its machinability rates fair (35/100) against poor (20/100) for Fe-Co 50 (unalloyed); for welding the order is 45 Permalloy first (good, 60/100) then Fe-Co 50 (unalloyed) (poor, 20/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 45 Permalloy and Fe-Co 50 (unalloyed) 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.