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Stainless Steel 304 vs S33550

Stainless Steel · grade comparison

Stainless Steel 304 and S33550 are both stainless steel grades. S33550 is the stronger of the two: yield strength 310 MPa (45 ksi) against 250 MPa (36.3 ksi) for 304, about 24% more; tensile strength follows at 690 MPa (100 ksi) vs 585 MPa (84.8 ksi). In exchange, 304 is the more ductile: elongation 55% versus 45% for S33550, and S33550 is harder (170 HB vs 150 HB). S33550 runs hotter in service (1,150°C vs 870°C continuous) and 304 conducts heat better (16.2 W/m·K vs 11.5 W/m·K). On the shop floor, 304 machines more easily (fair vs poor), 304 welds better (excellent vs very good), and 304 sits in a lower cost tier (standard, $$) than S33550 (high, $$$$).

304Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

S33550Choose it when strength drives the design, or when the part sees heat.

304 vs S33550: properties

304S33550

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

193 GPa28 Msi
200 GPa29 Msi

Bulk Modulus

152 GPa22 Msi
160 GPa23.2 Msi

Tensile Strength (Ultimate)

585 MPa84.8 ksi
690 MPa100 ksi

Yield Strength (0.2% offset)

250 MPa36.3 ksi
310 MPa45 ksi

Elongation at Break

55%
45%

Reduction in Area

70%
50%

Compressive Strength

250 MPa36.3 ksi
310 MPa45 ksi

Shear Strength

415 MPa60.2 ksi
450 MPa65.3 ksi

Fatigue Strength (Endurance Limit)

250 MPa36.3 ksi
280 MPa40.6 ksi

Fracture Toughness (K_IC)

220 MPa·√m200 ksi·√in
180 MPa·√m164 ksi·√in

Charpy V-Notch Impact (RT)

200 J148 ft·lbf
150 J111 ft·lbf

Hardness, Brinell

150 HB
170 HB

Hardness, Rockwell B

82 HRB
86 HRB

Hardness, Vickers

160 HV
180 HV

Same in both: Shear Modulus 77 GPa11.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Density

8 g/cm³0.29 lb/in³
8.14 g/cm³0.29 lb/in³

Melting Point (Solidus)

1,400°C2,552 °F
1,330°C2,426 °F

Liquidus Temperature

1,450°C2,642 °F
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
11.5 W/m·K6.6 BTU/hr·ft·°F

Specific Heat Capacity

500 J/kg·K0.12 BTU/lb·°F
460 J/kg·K0.11 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

17.3 µm/m·K9.6 µin/in·°F
14.4 µm/m·K8 µin/in·°F

Latent Heat of Fusion

285 J/g123 BTU/lb
—

Max Service Temperature (continuous)

870°C1,598 °F
1,150°C2,102 °F

Same in both: Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

2.4 % IACS
1.5 % IACS

Electrical Resistivity

7.2×10⁻⁷ Ω·m28.3 µΩ·in
1.16×10⁻⁶ Ω·m45.7 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.05 V
—

Corrosion Resistance

70 / 100
72 / 100

Manufacturability

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

Machinability

45 / 100
25 / 100

Machinability Rating (AISI 1212 = 100 %)

45%
15%

Weldability

88 / 100
75 / 100

Formability (cold)

90 / 100
65 / 100

Brazeability / Solderability

65 / 100
60 / 100

Polishability

88 / 100
70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

53 MJ/kg22,786 BTU/lb
115 MJ/kg49,441 BTU/lb

Embodied Carbon (primary production)

5.4 kg CO₂/kg
8.5 kg CO₂/kg

Embodied Water

110 L/kg13.2 gal/lb
200 L/kg24 gal/lb

Typical Recycled Content

70%
40%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

73 kN·m/kg
85 kN·m/kg

Specific Stiffness (E / density)

24.1 MN·m/kg
24.6 MN·m/kg

Modulus of Resilience

162 kJ/m³
240 kJ/m³

Thermal Diffusivity

4.1 mm²/s
3.1 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 scale304S33550

Manufacturing and finishing

Capability304S33550
CNC machiningYes—
Sheet metalYes—
Casting & forgingYes—
Default conditionAnnealed—
Relative cost$$ Standard$$$$ 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.

304 vs S33550 — frequently asked

Is S33550 stronger than 304?

Yes. S33550 has a typical yield strength of 310 MPa (45 ksi) against 250 MPa (36.3 ksi) for 304 — about 24% more. Tensile strength is 690 MPa (100 ksi) vs 585 MPa (84.8 ksi).

Which is cheaper, 304 or S33550?

304 is the lower-cost material: it sits in the standard tier ($$) while S33550 is high ($$$$). 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, 304 or S33550?

304. Its machinability rates fair (45/100) against poor (25/100) for S33550; for welding the order is 304 first (excellent, 88/100) then S33550 (very good, 75/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 304 and S33550 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.