Steel Alloy 79 vs FeMn
Steel · grade comparison
Steel Alloy 79 and FeMn are both steel grades. Alloy 79 is the stronger of the two: tensile strength 550 MPa (79.8 ksi) against 120 MPa (17.4 ksi) for FeMn, about 4.6 times as much. Alloy 79 is the more ductile: elongation 40% versus 0% for FeMn, and FeMn is harder (600 HB vs 120 HB). FeMn is lighter (7.1 g/cm³ vs 8.74 g/cm³ for Alloy 79) and Alloy 79 is stiffer (205 GPa vs 180 GPa). On the shop floor, Alloy 79 machines more easily (poor vs not recommended), Alloy 79 welds better (good vs not recommended), and FeMn sits in a lower cost tier (budget, $) than Alloy 79 (high, $$$$).
Alloy 79Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.
FeMnChoose it when weight is the constraint, or when cost is the deciding factor.
Alloy 79 vs FeMn: 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
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
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
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)
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 | Alloy 79 | FeMn |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $ Budget |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Both take the same 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.
Alloy 79 vs FeMn — frequently asked
Is Alloy 79 stronger than FeMn?
Yes. Alloy 79 has a typical tensile strength of 550 MPa (79.8 ksi) against 120 MPa (17.4 ksi) for FeMn — about 4.6 times as much.
Which is cheaper, Alloy 79 or FeMn?
FeMn is the lower-cost material: it sits in the budget tier ($) while Alloy 79 is high ($$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
Which is easier to machine, Alloy 79 or FeMn?
Alloy 79. Its machinability rates poor (32/100) against not recommended (5/100) for FeMn; for welding the order is Alloy 79 first (good, 60/100) then FeMn (not recommended, 5/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in Alloy 79 and FeMn 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.