Stainless Steel 409 vs S40977
Stainless Steel · grade comparison
Stainless Steel 409 and S40977 are both stainless steel grades. 409 is the stronger of the two: tensile strength 450 MPa (65.3 ksi) against 420 MPa (60.9 ksi) for S40977, about 7% more. On the shop floor, S40977 sits in a lower cost tier (budget, $) than 409 (premium, $$$).
409Choose it when strength drives the design.
S40977Choose it when cost is the deciding factor.
409 vs S40977: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all stainless 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 stainless 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)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Fracture Toughness (K_IC)
Same in both: Elastic (Young's) Modulus 200 GPa29 Msi · Shear Modulus 77 GPa11.2 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.3 · Yield Strength (0.2% offset) 250 MPa36.3 ksi · Elongation at Break 30% · Reduction in Area 65% · Compressive Strength 250 MPa36.3 ksi · Shear Strength 280 MPa40.6 ksi · Fatigue Strength (Endurance Limit) 230 MPa33.4 ksi · Hardness, Vickers 155 HV
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Liquidus Temperature
Thermal
How each material carries heat and how hot it can run.
Latent Heat of Fusion
Same in both: Thermal Conductivity 24.9 W/m·K14.4 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.7 µm/m·K6.5 µin/in·°F · Max Service Temperature (continuous) 675°C1,247 °F · Min Service Temperature -20°C-4 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 2.9 % IACS · Electrical Resistivity 6×10⁻⁷ Ω·m23.6 µΩ·in
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.
Weldability
Formability (cold)
Polishability
Same in both: Machinability 55 / 100 · Machinability Rating (AISI 1212 = 100 %) 65% · Brazeability / Solderability 60 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Typical Recycled Content
Same in both: Embodied Water 90 L/kg10.8 gal/lb
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Thermal Shock Resistance Index
Same in both: Modulus of Resilience 156 kJ/m³ · Thermal Diffusivity 7 mm²/s
Strength versus weight
Yield strength against density for every stainless steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Manufacturing and finishing
| Capability | 409 | S40977 |
|---|---|---|
| CNC machining | Yes | — |
| Sheet metal | Yes | — |
| Default condition | Annealed | — |
| Relative cost | $$$ Premium | $ Budget |
| Min. machined wall | 0.8 mm | — |
| Best machined surface | Ra 1.6 µm | — |
| AlCrN | Yes | — |
| AlTiN | Yes | — |
| Black Oxide | Yes | — |
| CVD Al2O3 | Yes | — |
| CVD TiCN | Yes | — |
| CVD TiN | Yes | — |
| Cerakote | Yes | — |
| Chrome Plating | Yes | — |
| CrN | Yes | — |
| DLC | Yes | — |
| Electropolishing | Yes | — |
| HVOF Coating | Yes | — |
| MoS2 | Yes | — |
| Multilayer CVD | Yes | — |
| Nickel Plating | Yes | — |
| PTFE Coating | Yes | — |
| Painting | Yes | — |
| Passivation (Stainless Steel) | Yes | — |
They share 7 finishes: Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Pickling, Plasma Spray, Silver Plating.
409 vs S40977 — frequently asked
Is 409 stronger than S40977?
Yes. 409 has a typical tensile strength of 450 MPa (65.3 ksi) against 420 MPa (60.9 ksi) for S40977 — about 7% more.
Which is cheaper, 409 or S40977?
S40977 is the lower-cost material: it sits in the budget tier ($) while 409 is premium ($$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
Which welds better, 409 or S40977?
S40977. Its weldability rates excellent (85/100) against very good (80/100) for 409.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 409 and S40977 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.