Steel Alloy 50 vs Super Invar
Steel · grade comparison
Steel Alloy 50 and Super Invar are both steel grades. Super Invar is the stronger of the two: yield strength 300 MPa (43.5 ksi) against 250 MPa (36.3 ksi) for Alloy 50, about 20% more. Alloy 50 is stiffer (160 GPa vs 145 GPa) and Alloy 50 runs hotter in service (400°C vs 150°C continuous). On the shop floor, Alloy 50 forms better (excellent vs very good).
Alloy 50Choose it when the part sees heat.
Super InvarChoose it when strength drives the design.
Alloy 50 vs Super Invar: 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
Compressive Strength
Shear Strength
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Vickers
Same in both: Fatigue Strength (Endurance Limit) 250 MPa36.3 ksi · Hardness, Rockwell B 80 HRB
Physical
Density and transition temperatures.
Density
Same in both: Melting Point (Solidus) 1,425°C2,597 °F · 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
Max Service Temperature (continuous)
Min Service Temperature
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)
Same in both: Brazeability / Solderability 70 / 100 · Polishability 65 / 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
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 50 | Super Invar |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Both take the same 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.
Alloy 50 vs Super Invar — frequently asked
Is Super Invar stronger than Alloy 50?
Yes. Super Invar has a typical yield strength of 300 MPa (43.5 ksi) against 250 MPa (36.3 ksi) for Alloy 50 — about 20% more. Tensile strength is 500 MPa (72.5 ksi) vs 520 MPa (75.4 ksi).
Which is cheaper, Alloy 50 or Super Invar?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, Alloy 50 or Super Invar?
Alloy 50. Its machinability rates fair (35/100) against poor (30/100) for Super Invar; for welding the order is Alloy 50 first (very good, 75/100) then Super Invar (very good, 70/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in Alloy 50 and Super Invar 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.