Steel 1J85 vs 4-79 Mo-Permalloy
Steel · grade comparison
Steel 1J85 and 4-79 Mo-Permalloy are both steel grades. 1J85 is the stronger of the two: tensile strength 600 MPa (87 ksi) against 550 MPa (79.8 ksi) for 4-79 Mo-Permalloy, about 9% more. 4-79 Mo-Permalloy is harder — 130 HV against 120 HV for 1J85 — which matters for wear surfaces and threads. 4-79 Mo-Permalloy runs hotter in service (400°C vs 200°C continuous). On the shop floor, 4-79 Mo-Permalloy welds better (good vs fair).
1J85Choose it when strength drives the design.
4-79 Mo-PermalloyChoose it when surface hardness matters, or when the part sees heat.
1J85 vs 4-79 Mo-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
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Reduction in Area
Compressive Strength
Shear Strength
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Same in both: Bulk Modulus 175 GPa25.4 Msi · Elongation at Break 40% · Fatigue Strength (Endurance Limit) 250 MPa36.3 ksi
Physical
Density and transition temperatures.
Density
Same in both: Melting Point (Solidus) 1,400°C2,552 °F · Liquidus Temperature 1,450°C2,642 °F
Thermal
How each material carries heat and how hot it can run.
Latent Heat of Fusion
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 19 W/m·K11 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.5 µm/m·K6.9 µin/in·°F · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 3.1 % IACS · Electrical Resistivity 5.5×10⁻⁷ Ω·m21.7 µΩ·in
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 Rating (AISI 1212 = 100 %)
Weldability
Brazeability / Solderability
Castability
Same in both: Machinability 30 / 100 · Formability (cold) 85 / 100 · Polishability 70 / 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 Shock Resistance Index
Same in both: Thermal Diffusivity 4.7 mm²/s
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 | 1J85 | 4-79 Mo-Permalloy |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Both take the same 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.
1J85 vs 4-79 Mo-Permalloy — frequently asked
Is 1J85 stronger than 4-79 Mo-Permalloy?
Yes. 1J85 has a typical tensile strength of 600 MPa (87 ksi) against 550 MPa (79.8 ksi) for 4-79 Mo-Permalloy — about 9% more.
Which is cheaper, 1J85 or 4-79 Mo-Permalloy?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which welds better, 1J85 or 4-79 Mo-Permalloy?
4-79 Mo-Permalloy. Its weldability rates good (60/100) against fair (50/100) for 1J85.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 1J85 and 4-79 Mo-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.