Steel 4-79 Mo-Permalloy vs 45 Permalloy
Steel · grade comparison
Steel 4-79 Mo-Permalloy and 45 Permalloy are both steel grades. 4-79 Mo-Permalloy is the stronger of the two: yield strength 260 MPa (37.7 ksi) against 210 MPa (30.5 ksi) for 45 Permalloy, about 24% more; tensile strength follows at 550 MPa (79.8 ksi) vs 520 MPa (75.4 ksi). 45 Permalloy is lighter (8.17 g/cm³ vs 8.74 g/cm³ for 4-79 Mo-Permalloy) and 4-79 Mo-Permalloy is stiffer (210 GPa vs 152 GPa).
4-79 Mo-PermalloyChoose it when strength drives the design.
45 PermalloyChoose it when weight is the constraint.
4-79 Mo-Permalloy vs 45 Permalloy: 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
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Reduction in Area
Fatigue Strength (Endurance Limit)
Hardness, Brinell
Hardness, Rockwell B
Shear Strength
Charpy V-Notch Impact (RT)
Same in both: Poisson's Ratio 0.3 · Elongation at Break 40% · Hardness, Vickers 130 HV
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Same in both: Liquidus Temperature 1,450°C2,642 °F
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
Same in both: Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -196°C-321 °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 %)
Formability (cold)
Castability
Brazeability / Solderability
Same in both: Weldability 60 / 100 · Polishability 70 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: Typical Recycled Content 20%
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 | 4-79 Mo-Permalloy | 45 Permalloy |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Both take the same 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.
4-79 Mo-Permalloy vs 45 Permalloy — frequently asked
Is 4-79 Mo-Permalloy stronger than 45 Permalloy?
Yes. 4-79 Mo-Permalloy has a typical yield strength of 260 MPa (37.7 ksi) against 210 MPa (30.5 ksi) for 45 Permalloy — about 24% more. Tensile strength is 550 MPa (79.8 ksi) vs 520 MPa (75.4 ksi).
Which is cheaper, 4-79 Mo-Permalloy or 45 Permalloy?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, 4-79 Mo-Permalloy or 45 Permalloy?
45 Permalloy. Its machinability rates fair (35/100) against poor (30/100) for 4-79 Mo-Permalloy.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 4-79 Mo-Permalloy and 45 Permalloy 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.