FabDigitFabDigit

Stainless Steel 303 vs S30435

Stainless Steel · grade comparison

Stainless Steel 303 and S30435 are both stainless steel grades. 303 is the stronger of the two: yield strength 450 MPa (65.3 ksi) against 300 MPa (43.5 ksi) for S30435, about 50% more. In exchange, S30435 is the more ductile: elongation 45% versus 30% for 303, and 303 is harder (240 HB vs 180 HB). On the shop floor, 303 machines more easily (very good vs fair), S30435 welds better (good vs poor), and 303 sits in a lower cost tier (premium, $$$) than S30435 (high, $$$$).

303Choose it when strength drives the design, or when the part is machined in volume.

S30435Choose it when the part is bent, formed or impact-loaded, or when it will be welded.

303 vs S30435: properties

303S30435

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

193 GPa28 Msi
197 GPa28.6 Msi

Shear Modulus

77 GPa11.2 Msi
76 GPa11 Msi

Bulk Modulus

140 GPa20.3 Msi
160 GPa23.2 Msi

Yield Strength (0.2% offset)

450 MPa65.3 ksi
300 MPa43.5 ksi

Elongation at Break

30%
45%

Reduction in Area

50%
65%

Compressive Strength

450 MPa65.3 ksi
305 MPa44.2 ksi

Fatigue Strength (Endurance Limit)

270 MPa39.2 ksi
250 MPa36.3 ksi

Fracture Toughness (K_IC)

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

Charpy V-Notch Impact (RT)

30 J22.1 ft·lbf
150 J111 ft·lbf

Hardness, Brinell

240 HB
180 HB

Hardness, Rockwell B

99 HRB
88 HRB

Hardness, Vickers

250 HV
190 HV

Same in both: Poisson's Ratio 0.29 · Tensile Strength (Ultimate) 655 MPa95 ksi · Shear Strength 420 MPa60.9 ksi

Physical

Density and transition temperatures.

Liquidus Temperature

1,420°C2,588 °F
1,450°C2,642 °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

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

Thermal Expansion (CTE, 20–100 °C)

17.3 µm/m·K9.6 µin/in·°F
16.8 µm/m·K9.3 µin/in·°F

Latent Heat of Fusion

275 J/g118 BTU/lb
270 J/g116 BTU/lb

Max Service Temperature (continuous)

760°C1,400 °F
700°C1,292 °F

Min Service Temperature

-100°C-148 °F
-196°C-321 °F

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

Electrical

Conductivity and insulation.

Electrical Conductivity

2.4 % IACS
2.3 % IACS

Electrical Resistivity

7.2×10⁻⁷ Ω·m28.3 µΩ·in
7.4×10⁻⁷ Ω·m29.1 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.1 V
-0.05 V

Corrosion Resistance

58 / 100
62 / 100

Manufacturability

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

Machinability

72 / 100
38 / 100

Machinability Rating (AISI 1212 = 100 %)

78%
38%

Weldability

25 / 100
68 / 100

Formability (cold)

40 / 100
70 / 100

Brazeability / Solderability

60 / 100
55 / 100

Polishability

40 / 100
75 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

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

Embodied Carbon (primary production)

5.5 kg CO₂/kg
4.6 kg CO₂/kg

Embodied Water

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

Typical Recycled Content

65%
45%

Common Calculations

Ratios derived from the values above.

Specific Stiffness (E / density)

24.4 MN·m/kg
24.9 MN·m/kg

Modulus of Resilience

525 kJ/m³
228 kJ/m³

Thermal Diffusivity

4.1 mm²/s
3.8 mm²/s

Same in both: Specific Strength (UTS / density) 83 kN·m/kg · 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 scale303S30435

Manufacturing and finishing

Capability303S30435
CNC machiningYes—
Default conditionCold Drawn—
Relative cost$$$ Premium$$$$ High
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.

303 vs S30435 — frequently asked

Is 303 stronger than S30435?

Yes. 303 has a typical yield strength of 450 MPa (65.3 ksi) against 300 MPa (43.5 ksi) for S30435 — about 50% more. Tensile strength is 655 MPa (95 ksi) vs 655 MPa (95 ksi).

Which is cheaper, 303 or S30435?

303 is the lower-cost material: it sits in the premium tier ($$$) while S30435 is high ($$$$). 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, 303 or S30435?

303. Its machinability rates very good (72/100) against fair (38/100) for S30435; for welding the order is S30435 first (good, 68/100) then 303 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 303 and S30435 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.