FabDigitFabDigit

Stainless Steel 409 vs 445

Stainless Steel · grade comparison

Stainless Steel 409 and 445 are both stainless steel grades. 445 is the stronger of the two: yield strength 330 MPa (47.9 ksi) against 250 MPa (36.3 ksi) for 409, about 32% more; tensile strength follows at 480 MPa (69.6 ksi) vs 450 MPa (65.3 ksi). 445 is harder — 170 HB against 150 HB for 409 — which matters for wear surfaces and threads. 445 runs hotter in service (800°C vs 675°C continuous) and 409 conducts heat better (24.9 W/m·K vs 22 W/m·K). On the shop floor, 409 welds better (very good vs good).

409Choose it when it will be welded.

445Choose it when strength drives the design, or when surface hardness matters.

409 vs 445: properties

409445

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

450 MPa65.3 ksi
480 MPa69.6 ksi

Yield Strength (0.2% offset)

250 MPa36.3 ksi
330 MPa47.9 ksi

Compressive Strength

250 MPa36.3 ksi
—

Shear Strength

280 MPa40.6 ksi
300 MPa43.5 ksi

Fatigue Strength (Endurance Limit)

230 MPa33.4 ksi
240 MPa34.8 ksi

Charpy V-Notch Impact (RT)

40 J29.5 ft·lbf
60 J44.3 ft·lbf

Hardness, Brinell

150 HB
170 HB

Hardness, Rockwell B

80 HRB
85 HRB

Hardness, Vickers

155 HV
175 HV

Fracture Toughness (K_IC)

—
60 MPa·√m54.6 ksi·√in

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 · Elongation at Break 30% · Reduction in Area 65%

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
22 W/m·K12.7 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

Max Service Temperature (continuous)

675°C1,247 °F
800°C1,472 °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)

-0.35 V
-0.1 V

Corrosion Resistance

40 / 100
78 / 100

Manufacturability

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

Machinability

55 / 100
48 / 100

Machinability Rating (AISI 1212 = 100 %)

65%
50%

Weldability

80 / 100
62 / 100

Formability (cold)

78 / 100
72 / 100

Polishability

55 / 100
78 / 100

Same in both: Brazeability / Solderability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

40 MJ/kg17,197 BTU/lb
46 MJ/kg19,776 BTU/lb

Embodied Carbon (primary production)

2.9 kg CO₂/kg
3.4 kg CO₂/kg

Embodied Water

90 L/kg10.8 gal/lb
100 L/kg12 gal/lb

Typical Recycled Content

65%
60%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

58 kN·m/kg
62 kN·m/kg

Modulus of Resilience

156 kJ/m³
272 kJ/m³

Thermal Diffusivity

7 mm²/s
6.2 mm²/s

Same in both: Specific Stiffness (E / density) 26 MN·m/kg · 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 scale445409

Manufacturing and finishing

Capability409445
CNC machiningYes—
Sheet metalYes—
Default conditionAnnealed—
Relative cost$$$ Premium$$$ Premium
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 445 — frequently asked

Is 445 stronger than 409?

Yes. 445 has a typical yield strength of 330 MPa (47.9 ksi) against 250 MPa (36.3 ksi) for 409 — about 32% more. Tensile strength is 480 MPa (69.6 ksi) vs 450 MPa (65.3 ksi).

Which is cheaper, 409 or 445?

Both sit in the same relative cost tier ($$$, premium); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, 409 or 445?

409. Its machinability rates good (55/100) against fair (48/100) for 445; for welding the order is 409 first (very good, 80/100) then 445 (good, 62/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 409 and 445 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.