Steel ER70S-2 vs ER90S-D2
Steel · grade comparison
Steel ER70S-2 and ER90S-D2 are both steel grades. ER90S-D2 is the stronger of the two: yield strength 570 MPa (82.7 ksi) against 450 MPa (65.3 ksi) for ER70S-2, about 27% more; tensile strength follows at 660 MPa (95.7 ksi) vs 560 MPa (81.2 ksi). In exchange, ER70S-2 is the more ductile: elongation 28% versus 23% for ER90S-D2, and ER90S-D2 is harder (210 HB vs 155 HB). ER70S-2 conducts heat better (48 W/m·K vs 42 W/m·K). On the shop floor, ER70S-2 machines more easily (good vs fair).
ER70S-2Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
ER90S-D2Choose it when strength drives the design.
ER70S-2 vs ER90S-D2: 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.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Hardness, Rockwell C
Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29
Physical
Density and transition temperatures.
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,470°C2,678 °F · Liquidus Temperature 1,520°C2,768 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Latent Heat of Fusion
Min Service Temperature
Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.5 µm/m·K6.9 µin/in·°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
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)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
Same in both: Specific Stiffness (E / density) 26.1 MN·m/kg
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 | ER70S-2 | ER90S-D2 |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$ Standard | $$ Standard |
| 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.
ER70S-2 vs ER90S-D2 — frequently asked
Is ER90S-D2 stronger than ER70S-2?
Yes. ER90S-D2 has a typical yield strength of 570 MPa (82.7 ksi) against 450 MPa (65.3 ksi) for ER70S-2 — about 27% more. Tensile strength is 660 MPa (95.7 ksi) vs 560 MPa (81.2 ksi).
Which is cheaper, ER70S-2 or ER90S-D2?
Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, ER70S-2 or ER90S-D2?
ER70S-2. Its machinability rates good (62/100) against fair (45/100) for ER90S-D2; for welding the order is ER70S-2 first (excellent, 98/100) then ER90S-D2 (excellent, 90/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in ER70S-2 and ER90S-D2 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.