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Stainless Steel 304 vs SUS317J2

Stainless Steel · grade comparison

Stainless Steel 304 and SUS317J2 are both stainless steel grades. SUS317J2 is the stronger of the two: yield strength 390 MPa (56.6 ksi) against 250 MPa (36.3 ksi) for 304, about 56% more; tensile strength follows at 720 MPa (104 ksi) vs 585 MPa (84.8 ksi). In exchange, 304 is the more ductile: elongation 55% versus 48% for SUS317J2, and SUS317J2 is harder (180 HB vs 150 HB). 304 runs hotter in service (870°C vs 550°C continuous) and 304 conducts heat better (16.2 W/m·K vs 13 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, $$) than SUS317J2 (high, $$$$).

304Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

SUS317J2Choose it when strength drives the design.

304 vs SUS317J2: properties

304SUS317J2

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

193 GPa28 Msi
195 GPa28.3 Msi

Shear Modulus

77 GPa11.2 Msi
76 GPa11 Msi

Bulk Modulus

152 GPa22 Msi
160 GPa23.2 Msi

Tensile Strength (Ultimate)

585 MPa84.8 ksi
720 MPa104 ksi

Yield Strength (0.2% offset)

250 MPa36.3 ksi
390 MPa56.6 ksi

Elongation at Break

55%
48%

Reduction in Area

70%
65%

Compressive Strength

250 MPa36.3 ksi
—

Shear Strength

415 MPa60.2 ksi
470 MPa68.2 ksi

Fatigue Strength (Endurance Limit)

250 MPa36.3 ksi
300 MPa43.5 ksi

Fracture Toughness (K_IC)

220 MPa·√m200 ksi·√in
—

Charpy V-Notch Impact (RT)

200 J148 ft·lbf
180 J133 ft·lbf

Hardness, Brinell

150 HB
180 HB

Hardness, Rockwell B

82 HRB
90 HRB

Hardness, Vickers

160 HV
190 HV

Same in both: Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,400°C2,552 °F
1,370°C2,498 °F

Liquidus Temperature

1,450°C2,642 °F
1,400°C2,552 °F

Same in both: Density 8 g/cm³0.29 lb/in³

Thermal

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

Thermal Conductivity

16.2 W/m·K9.4 BTU/hr·ft·°F
13 W/m·K7.5 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

17.3 µm/m·K9.6 µin/in·°F
16 µm/m·K8.9 µin/in·°F

Latent Heat of Fusion

285 J/g123 BTU/lb
270 J/g116 BTU/lb

Max Service Temperature (continuous)

870°C1,598 °F
550°C1,022 °F

Same in both: Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

2.4 % IACS
2 % IACS

Electrical Resistivity

7.2×10⁻⁷ Ω·m28.3 µΩ·in
8.5×10⁻⁷ Ω·m33.5 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

70 / 100
82 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.05 V

Manufacturability

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

Machinability

45 / 100
30 / 100

Machinability Rating (AISI 1212 = 100 %)

45%
30%

Weldability

88 / 100
70 / 100

Formability (cold)

90 / 100
65 / 100

Brazeability / Solderability

65 / 100
60 / 100

Polishability

88 / 100
80 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

53 MJ/kg22,786 BTU/lb
60 MJ/kg25,795 BTU/lb

Embodied Carbon (primary production)

5.4 kg CO₂/kg
4.5 kg CO₂/kg

Embodied Water

110 L/kg13.2 gal/lb
130 L/kg15.6 gal/lb

Typical Recycled Content

70%
55%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

73 kN·m/kg
90 kN·m/kg

Specific Stiffness (E / density)

24.1 MN·m/kg
24.4 MN·m/kg

Modulus of Resilience

162 kJ/m³
390 kJ/m³

Thermal Diffusivity

4.1 mm²/s
3.3 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 scale304SUS317J2

Manufacturing and finishing

Capability304SUS317J2
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 SUS317J2 — frequently asked

Is SUS317J2 stronger than 304?

Yes. SUS317J2 has a typical yield strength of 390 MPa (56.6 ksi) against 250 MPa (36.3 ksi) for 304 — about 56% more. Tensile strength is 720 MPa (104 ksi) vs 585 MPa (84.8 ksi).

Which is cheaper, 304 or SUS317J2?

304 is the lower-cost material: it sits in the standard tier ($$) while SUS317J2 is high ($$$$). 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 SUS317J2?

304. Its machinability rates fair (45/100) against poor (30/100) for SUS317J2; for welding the order is 304 first (excellent, 88/100) then SUS317J2 (very good, 70/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 304 and SUS317J2 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.