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Stainless Steel 1.4590 vs 409

Stainless Steel · grade comparison

Stainless Steel 1.4590 and 409 are both stainless steel grades. 1.4590 is the stronger of the two: yield strength 290 MPa (42.1 ksi) against 250 MPa (36.3 ksi) for 409, about 16% more. 1.4590 is harder — 165 HV against 155 HV for 409 — which matters for wear surfaces and threads. 1.4590 is stiffer (220 GPa vs 200 GPa) and 1.4590 runs hotter in service (900°C vs 675°C continuous). On the shop floor, 1.4590 sits in a lower cost tier (standard, $$) than 409 (premium, $$$).

1.4590Choose it when strength drives the design, or when surface hardness matters.

1.4590 vs 409: properties

1.4590409

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

220 GPa31.9 Msi
200 GPa29 Msi

Shear Modulus

85 GPa12.3 Msi
77 GPa11.2 Msi

Tensile Strength (Ultimate)

470 MPa68.2 ksi
450 MPa65.3 ksi

Yield Strength (0.2% offset)

290 MPa42.1 ksi
250 MPa36.3 ksi

Shear Strength

320 MPa46.4 ksi
280 MPa40.6 ksi

Fatigue Strength (Endurance Limit)

240 MPa34.8 ksi
230 MPa33.4 ksi

Charpy V-Notch Impact (RT)

60 J44.3 ft·lbf
40 J29.5 ft·lbf

Hardness, Brinell

155 HB
150 HB

Hardness, Rockwell B

82 HRB
80 HRB

Hardness, Vickers

165 HV
155 HV

Compressive Strength

—
250 MPa36.3 ksi

Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.3 · Elongation at Break 30% · Reduction in Area 65%

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,425°C2,597 °F
1,482°C2,700 °F

Liquidus Temperature

1,510°C2,750 °F
1,532°C2,790 °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

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

Thermal Expansion (CTE, 20–100 °C)

10 µm/m·K5.6 µin/in·°F
11.7 µm/m·K6.5 µin/in·°F

Max Service Temperature (continuous)

900°C1,652 °F
675°C1,247 °F

Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Latent Heat of Fusion 260 J/g112 BTU/lb · 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)

-0.15 V
-0.35 V

Corrosion Resistance

55 / 100
40 / 100

Manufacturability

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

Machinability

50 / 100
55 / 100

Machinability Rating (AISI 1212 = 100 %)

55%
65%

Formability (cold)

70 / 100
78 / 100

Brazeability / Solderability

70 / 100
60 / 100

Polishability

65 / 100
55 / 100

Same in both: Weldability 80 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

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

Embodied Carbon (primary production)

3.4 kg CO₂/kg
2.9 kg CO₂/kg

Embodied Water

110 L/kg13.2 gal/lb
90 L/kg10.8 gal/lb

Typical Recycled Content

70%
65%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

61 kN·m/kg
58 kN·m/kg

Specific Stiffness (E / density)

28.6 MN·m/kg
26 MN·m/kg

Modulus of Resilience

191 kJ/m³
156 kJ/m³

Thermal Diffusivity

7.1 mm²/s
7 mm²/s

Same in both: Thermal Shock Resistance Index 5

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 scale1.4590409

Manufacturing and finishing

Capability1.4590409
CNC machining—Yes
Sheet metal—Yes
Default condition—Annealed
Relative cost$$ Standard$$$ Premium
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.

1.4590 vs 409 — frequently asked

Is 1.4590 stronger than 409?

Yes. 1.4590 has a typical yield strength of 290 MPa (42.1 ksi) against 250 MPa (36.3 ksi) for 409 — about 16% more. Tensile strength is 470 MPa (68.2 ksi) vs 450 MPa (65.3 ksi).

Which is cheaper, 1.4590 or 409?

1.4590 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, 1.4590 or 409?

409. Its machinability rates good (55/100) against fair (50/100) for 1.4590.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 1.4590 and 409 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.