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Stainless Steel 1.4307 vs 303

Stainless Steel · grade comparison

Stainless Steel 1.4307 and 303 are both stainless steel grades. 303 is the stronger of the two: yield strength 450 MPa (65.3 ksi) against 290 MPa (42.1 ksi) for 1.4307, about 55% more; tensile strength follows at 655 MPa (95 ksi) vs 580 MPa (84.1 ksi). In exchange, 1.4307 is the more ductile: elongation 55% versus 30% for 303, and 303 is harder (240 HB vs 150 HB). 303 runs hotter in service (760°C vs 425°C continuous). On the shop floor, 303 machines more easily (very good vs fair), 1.4307 welds better (excellent vs poor), and 1.4307 sits in a lower cost tier (standard, $$) than 303 (premium, $$$).

1.4307Choose 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.

1.4307 vs 303: properties

1.4307303

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

200 GPa29 Msi
193 GPa28 Msi

Bulk Modulus

145 GPa21 Msi
140 GPa20.3 Msi

Tensile Strength (Ultimate)

580 MPa84.1 ksi
655 MPa95 ksi

Yield Strength (0.2% offset)

290 MPa42.1 ksi
450 MPa65.3 ksi

Elongation at Break

55%
30%

Reduction in Area

70%
50%

Compressive Strength

290 MPa42.1 ksi
450 MPa65.3 ksi

Fatigue Strength (Endurance Limit)

240 MPa34.8 ksi
270 MPa39.2 ksi

Fracture Toughness (K_IC)

200 MPa·√m182 ksi·√in
100 MPa·√m91 ksi·√in

Charpy V-Notch Impact (RT)

180 J133 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

150 HB
240 HB

Hardness, Rockwell B

80 HRB
99 HRB

Hardness, Vickers

160 HV
250 HV

Same in both: Shear Modulus 77 GPa11.2 Msi · Poisson's Ratio 0.29 · Shear Strength 420 MPa60.9 ksi

Physical

Density and transition temperatures.

Liquidus Temperature

1,450°C2,642 °F
1,420°C2,588 °F

Same in both: Density 7.9 g/cm³0.29 lb/in³ · 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 µm/m·K8.9 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)

425°C797 °F
760°C1,400 °F

Min Service Temperature

-196°C-321 °F
-100°C-148 °F

Same in both: Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°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)

-0.05 V
-0.1 V

Corrosion Resistance

65 / 100
58 / 100

Manufacturability

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

Machinability

38 / 100
72 / 100

Machinability Rating (AISI 1212 = 100 %)

45%
78%

Weldability

95 / 100
25 / 100

Formability (cold)

92 / 100
40 / 100

Brazeability / Solderability

65 / 100
60 / 100

Polishability

85 / 100
40 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

55 MJ/kg23,646 BTU/lb
53 MJ/kg22,786 BTU/lb

Embodied Carbon (primary production)

3.6 kg CO₂/kg
5.5 kg CO₂/kg

Embodied Water

200 L/kg24 gal/lb
150 L/kg18 gal/lb

Same in both: Typical Recycled Content 65%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

73 kN·m/kg
83 kN·m/kg

Specific Stiffness (E / density)

25.3 MN·m/kg
24.4 MN·m/kg

Modulus of Resilience

210 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 scale3031.4307

Manufacturing and finishing

Capability1.4307303
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.

1.4307 vs 303 — frequently asked

Is 303 stronger than 1.4307?

Yes. 303 has a typical yield strength of 450 MPa (65.3 ksi) against 290 MPa (42.1 ksi) for 1.4307 — about 55% more. Tensile strength is 655 MPa (95 ksi) vs 580 MPa (84.1 ksi).

Which is cheaper, 1.4307 or 303?

1.4307 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, 1.4307 or 303?

303. Its machinability rates very good (72/100) against fair (38/100) for 1.4307; for welding the order is 1.4307 first (excellent, 95/100) then 303 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 1.4307 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.