Steel A2 vs S7
Steel · grade comparison
Steel A2 and S7 are both steel grades, both tool steel. S7 is the stronger of the two: yield strength 530 MPa (76.9 ksi) against 470 MPa (68.2 ksi) for A2, about 13% more; tensile strength follows at 830 MPa (120 ksi) vs 740 MPa (107 ksi). In exchange, A2 is the more ductile: elongation 22% versus 18% for S7, and A2 is harder (217 HB vs 200 HB). S7 runs hotter in service (500°C vs 425°C continuous). On the shop floor, S7 welds better (30 vs 20 out of 100) and A2 sits in a lower cost tier (premium, $$$) than S7 (specialty, $$$$$).
A2Choose it when the part is bent, formed or impact-loaded, or when cost is the deciding factor.
S7Choose it when strength drives the design, or when the part sees heat.
A2 vs S7: 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)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Fracture Toughness (K_IC)
Hardness, Rockwell C
Same in both: Bulk Modulus 160 GPa23.2 Msi
Physical
Density and transition temperatures.
Density
Liquidus Temperature
Same in both: Melting Point (Solidus) 1,420°C2,588 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Max Service Temperature (continuous)
Min Service Temperature
Same in both: Thermal Conductivity 26 W/m·K15 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Castability
Polishability
Same in both: Formability (cold) 35 / 100 · Brazeability / Solderability 40 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Carbon (primary production)
Typical Recycled Content
Same in both: Embodied Energy (primary production) 36 MJ/kg15,477 BTU/lb · Embodied Water 65 L/kg7.8 gal/lb
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 7.2 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 | A2 | S7 |
|---|---|---|
| Default condition | Annealed | Annealed |
| Relative cost | $$$ Premium | $$$$$ Specialty |
| Min. machined wall | 0.8 mm | 0.8 mm |
| Best machined surface | Ra 1.6 µm | Ra 1.6 µm |
Both are offered for CNC machining. Both take the same 38 finishes: AlCrN, AlTiN, Black Oxide, CVD Al2O3, CVD TiCN, CVD TiN, Cerakote, Chrome Plating, Copper Plating, CrN, DLC, E-Coating and 26 more.
A2 vs S7 — frequently asked
Is S7 stronger than A2?
Yes. S7 has a typical yield strength of 530 MPa (76.9 ksi) against 470 MPa (68.2 ksi) for A2 — about 13% more. Tensile strength is 830 MPa (120 ksi) vs 740 MPa (107 ksi).
Which is cheaper, A2 or S7?
A2 is the lower-cost material: it sits in the premium tier ($$$) while S7 is specialty ($$$$$). 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, A2 or S7?
S7, by a small margin. Both rate fair for machinability — 50/100 against 45/100 for A2; for welding the order is S7 first (poor, 30/100) then A2 (poor, 20/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in A2 and S7 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.