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Stainless Steel 1.4371 vs 303

Stainless Steel · grade comparison

Stainless Steel 1.4371 and 303 are both stainless steel grades. 303 is the stronger of the two: yield strength 450 MPa (65.3 ksi) against 420 MPa (60.9 ksi) for 1.4371, about 7% more. In exchange, 1.4371 is the more ductile: elongation 50% versus 30% for 303, and 303 is harder (240 HB vs 195 HB). 303 runs hotter in service (760°C vs 550°C continuous). On the shop floor, 303 machines more easily (very good vs poor), 1.4371 welds better (very good vs poor), and 1.4371 sits in a lower cost tier (standard, $$) than 303 (premium, $$$).

1.4371Choose it when the part is bent, formed or impact-loaded, or when it will be welded.

303Choose it when strength drives the design, or when the part sees heat.

1.4371 vs 303: properties

1.4371303

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

200 GPa29 Msi
193 GPa28 Msi

Bulk Modulus

155 GPa22.5 Msi
140 GPa20.3 Msi

Poisson's Ratio

0.3
0.29

Tensile Strength (Ultimate)

750 MPa109 ksi
655 MPa95 ksi

Yield Strength (0.2% offset)

420 MPa60.9 ksi
450 MPa65.3 ksi

Elongation at Break

50%
30%

Reduction in Area

65%
50%

Compressive Strength

420 MPa60.9 ksi
450 MPa65.3 ksi

Shear Strength

470 MPa68.2 ksi
420 MPa60.9 ksi

Fatigue Strength (Endurance Limit)

320 MPa46.4 ksi
270 MPa39.2 ksi

Fracture Toughness (K_IC)

160 MPa·√m146 ksi·√in
100 MPa·√m91 ksi·√in

Charpy V-Notch Impact (RT)

110 J81.1 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

195 HB
240 HB

Hardness, Rockwell B

94 HRB
99 HRB

Hardness, Vickers

205 HV
250 HV

Same in both: Shear Modulus 77 GPa11.2 Msi

Physical

Density and transition temperatures.

Density

7.8 g/cm³0.28 lb/in³
7.9 g/cm³0.29 lb/in³

Liquidus Temperature

1,450°C2,642 °F
1,420°C2,588 °F

Same in both: Melting Point (Solidus) 1,400°C2,552 °F

Thermal

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

Thermal Conductivity

15 W/m·K8.7 BTU/hr·ft·°F
16.2 W/m·K9.4 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

16.5 µm/m·K9.2 µin/in·°F
17.3 µm/m·K9.6 µin/in·°F

Latent Heat of Fusion

285 J/g123 BTU/lb
275 J/g118 BTU/lb

Max Service Temperature (continuous)

550°C1,022 °F
760°C1,400 °F

Same in both: Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Min Service Temperature -100°C-148 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 2.4 % IACS · Electrical Resistivity 7.2×10⁻⁷ Ω·m28.3 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.15 V
-0.1 V

Corrosion Resistance

48 / 100
58 / 100

Manufacturability

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

Machinability

32 / 100
72 / 100

Machinability Rating (AISI 1212 = 100 %)

40%
78%

Weldability

78 / 100
25 / 100

Formability (cold)

82 / 100
40 / 100

Polishability

70 / 100
40 / 100

Same in both: Brazeability / Solderability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

46 MJ/kg19,776 BTU/lb
53 MJ/kg22,786 BTU/lb

Embodied Carbon (primary production)

3.4 kg CO₂/kg
5.5 kg CO₂/kg

Embodied Water

120 L/kg14.4 gal/lb
150 L/kg18 gal/lb

Typical Recycled Content

60%
65%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

96 kN·m/kg
83 kN·m/kg

Specific Stiffness (E / density)

25.6 MN·m/kg
24.4 MN·m/kg

Modulus of Resilience

441 kJ/m³
525 kJ/m³

Thermal Diffusivity

3.8 mm²/s
4.1 mm²/s

Same in both: Thermal Shock Resistance Index 3

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 scale3031.4371

Manufacturing and finishing

Capability1.4371303
CNC machining—Yes
Default condition—Cold Drawn
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.

1.4371 vs 303 — frequently asked

Is 303 stronger than 1.4371?

Yes. 303 has a typical yield strength of 450 MPa (65.3 ksi) against 420 MPa (60.9 ksi) for 1.4371 — about 7% more. Tensile strength is 655 MPa (95 ksi) vs 750 MPa (109 ksi).

Which is cheaper, 1.4371 or 303?

1.4371 is the lower-cost material: it sits in the standard tier ($$) while 303 is premium ($$$). 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, 1.4371 or 303?

303. Its machinability rates very good (72/100) against poor (32/100) for 1.4371; for welding the order is 1.4371 first (very good, 78/100) then 303 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 1.4371 and 303 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.