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Stainless Steel 409 vs 430FSe

Stainless Steel · grade comparison

Stainless Steel 409 and 430FSe are both stainless steel grades. 430FSe is the stronger of the two: yield strength 310 MPa (45 ksi) against 250 MPa (36.3 ksi) for 409, about 24% more; tensile strength follows at 520 MPa (75.4 ksi) vs 450 MPa (65.3 ksi). In exchange, 409 is the more ductile: elongation 30% versus 25% for 430FSe, and 430FSe is harder (175 HB vs 150 HB). On the shop floor, 430FSe machines more easily (66 vs 55 out of 100), 409 welds better (very good vs poor), and 430FSe sits in a lower cost tier (standard, $$) than 409 (premium, $$$).

409Choose it when the part is bent, formed or impact-loaded, or when it will be welded.

430FSeChoose it when strength drives the design, or when the part is machined in volume.

409 vs 430FSe: properties

409430FSe

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Poisson's Ratio

0.3
0.28

Tensile Strength (Ultimate)

450 MPa65.3 ksi
520 MPa75.4 ksi

Yield Strength (0.2% offset)

250 MPa36.3 ksi
310 MPa45 ksi

Elongation at Break

30%
25%

Reduction in Area

65%
55%

Compressive Strength

250 MPa36.3 ksi
—

Shear Strength

280 MPa40.6 ksi
360 MPa52.2 ksi

Fatigue Strength (Endurance Limit)

230 MPa33.4 ksi
250 MPa36.3 ksi

Charpy V-Notch Impact (RT)

40 J29.5 ft·lbf
15 J11.1 ft·lbf

Hardness, Brinell

150 HB
175 HB

Hardness, Rockwell B

80 HRB
86 HRB

Hardness, Vickers

155 HV
—

Same in both: Elastic (Young's) Modulus 200 GPa29 Msi · Shear Modulus 77 GPa11.2 Msi · Bulk Modulus 160 GPa23.2 Msi

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,482°C2,700 °F
1,425°C2,597 °F

Liquidus Temperature

1,532°C2,790 °F
1,510°C2,750 °F

Same in both: Density 7.7 g/cm³0.28 lb/in³

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

24.9 W/m·K14.4 BTU/hr·ft·°F
26 W/m·K15 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

11.7 µm/m·K6.5 µin/in·°F
10.4 µm/m·K5.8 µin/in·°F

Latent Heat of Fusion

260 J/g112 BTU/lb
270 J/g116 BTU/lb

Max Service Temperature (continuous)

675°C1,247 °F
700°C1,292 °F

Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°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)

-0.35 V
-0.25 V

Corrosion Resistance

40 / 100
45 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

55 / 100
66 / 100

Machinability Rating (AISI 1212 = 100 %)

65%
70%

Weldability

80 / 100
18 / 100

Formability (cold)

78 / 100
30 / 100

Brazeability / Solderability

60 / 100
45 / 100

Polishability

55 / 100
72 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

40 MJ/kg17,197 BTU/lb
52 MJ/kg22,356 BTU/lb

Embodied Carbon (primary production)

2.9 kg CO₂/kg
3.6 kg CO₂/kg

Embodied Water

90 L/kg10.8 gal/lb
200 L/kg24 gal/lb

Typical Recycled Content

65%
60%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

58 kN·m/kg
68 kN·m/kg

Modulus of Resilience

156 kJ/m³
240 kJ/m³

Thermal Diffusivity

7 mm²/s
7.3 mm²/s

Thermal Shock Resistance Index

5
7

Same in both: Specific Stiffness (E / density) 26 MN·m/kg

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.

3005007001,0001,5002,0007.27.47.67.888.2Density (g/cm³)Yield strength (MPa) — log scale430FSe409

Manufacturing and finishing

Capability409430FSe
CNC machiningYes—
Sheet metalYes—
Default conditionAnnealed—
Relative cost$$$ Premium$$ Standard
Min. machined wall0.8 mm—
Best machined surfaceRa 1.6 µm—
AlCrNYes—
AlTiNYes—
Black OxideYes—
CVD Al2O3Yes—
CVD TiCNYes—
CVD TiNYes—
CerakoteYes—
Chrome PlatingYes—
CrNYes—
DLCYes—
ElectropolishingYes—
HVOF CoatingYes—
MoS2Yes—
Multilayer CVDYes—
Nickel PlatingYes—
PTFE CoatingYes—
PaintingYes—
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 430FSe — frequently asked

Is 430FSe stronger than 409?

Yes. 430FSe has a typical yield strength of 310 MPa (45 ksi) against 250 MPa (36.3 ksi) for 409 — about 24% more. Tensile strength is 520 MPa (75.4 ksi) vs 450 MPa (65.3 ksi).

Which is cheaper, 409 or 430FSe?

430FSe is the lower-cost material: it sits in the standard 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 is easier to machine, 409 or 430FSe?

430FSe, by a small margin. Both rate good for machinability — 66/100 against 55/100 for 409; for welding the order is 409 first (very good, 80/100) then 430FSe (poor, 18/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 409 and 430FSe 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.