Steel 1J34 vs 4-79 Mo-Permalloy
Steel · grade comparison
Steel 1J34 and 4-79 Mo-Permalloy are both steel grades. Both yield at about 260 MPa — strength does not separate them. 4-79 Mo-Permalloy is the more ductile: elongation 40% versus 30% for 1J34, and 1J34 is harder (130 HB vs 120 HB). 1J34 is lighter (8.2 g/cm³ vs 8.74 g/cm³ for 4-79 Mo-Permalloy) and 4-79 Mo-Permalloy is stiffer (210 GPa vs 185 GPa).
1J34Choose it when weight is the constraint.
4-79 Mo-PermalloyChoose it when the part is bent, formed or impact-loaded.
1J34 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
Bulk Modulus
Tensile Strength (Ultimate)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Same in both: Poisson's Ratio 0.3 · Yield Strength (0.2% offset) 260 MPa37.7 ksi · Fatigue Strength (Endurance Limit) 250 MPa36.3 ksi
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
Min Service Temperature
Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · 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 Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Castability
Brazeability / Solderability
Same in both: Machinability 30 / 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 Diffusivity
Same in both: Thermal Shock Resistance Index 4
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 | 1J34 | 4-79 Mo-Permalloy |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Both take the same 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.
1J34 vs 4-79 Mo-Permalloy — frequently asked
What is the difference between 1J34 and 4-79 Mo-Permalloy?
Steel 1J34 and 4-79 Mo-Permalloy are both steel grades. Both yield at about 260 MPa — strength does not separate them. 4-79 Mo-Permalloy is the more ductile: elongation 40% versus 30% for 1J34, and 1J34 is harder (130 HB vs 120 HB).
Which is cheaper, 1J34 or 4-79 Mo-Permalloy?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which welds better, 1J34 or 4-79 Mo-Permalloy?
4-79 Mo-Permalloy. Its weldability rates good (60/100) against good (55/100) for 1J34.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 1J34 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.