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Stainless Steel 303 vs SUS316J1L

Stainless Steel · grade comparison

Stainless Steel 303 and SUS316J1L are both stainless steel grades. 303 is the stronger of the two: yield strength 450 MPa (65.3 ksi) against 250 MPa (36.3 ksi) for SUS316J1L, about 80% more; tensile strength follows at 655 MPa (95 ksi) vs 545 MPa (79 ksi). In exchange, SUS316J1L 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 500°C continuous). On the shop floor, 303 machines more easily (very good vs fair) and SUS316J1L welds better (excellent vs poor).

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

SUS316J1LChoose it when the part is bent, formed or impact-loaded, or when it will be welded.

303 vs SUS316J1L: properties

303SUS316J1L

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Bulk Modulus

140 GPa20.3 Msi
160 GPa23.2 Msi

Poisson's Ratio

0.29
0.3

Tensile Strength (Ultimate)

655 MPa95 ksi
545 MPa79 ksi

Yield Strength (0.2% offset)

450 MPa65.3 ksi
250 MPa36.3 ksi

Elongation at Break

30%
55%

Reduction in Area

50%
70%

Compressive Strength

450 MPa65.3 ksi
250 MPa36.3 ksi

Shear Strength

420 MPa60.9 ksi
350 MPa50.8 ksi

Fatigue Strength (Endurance Limit)

270 MPa39.2 ksi
240 MPa34.8 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
160 J118 ft·lbf

Hardness, Brinell

240 HB
150 HB

Hardness, Rockwell B

99 HRB
78 HRB

Hardness, Vickers

250 HV
160 HV

Same in both: Elastic (Young's) Modulus 193 GPa28 Msi · Shear Modulus 77 GPa11.2 Msi

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,400°C2,552 °F
1,375°C2,507 °F

Liquidus Temperature

1,420°C2,588 °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
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 µm/m·K8.9 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
500°C932 °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
7.5×10⁻⁷ Ω·m29.5 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.1 V
-0.08 V

Corrosion Resistance

58 / 100
76 / 100

Manufacturability

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

Machinability

72 / 100
35 / 100

Machinability Rating (AISI 1212 = 100 %)

78%
36%

Weldability

25 / 100
88 / 100

Formability (cold)

40 / 100
92 / 100

Brazeability / Solderability

60 / 100
65 / 100

Polishability

40 / 100
80 / 100

Castability

—
40 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

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

Embodied Water

150 L/kg18 gal/lb
110 L/kg13.2 gal/lb

Same in both: Embodied Carbon (primary production) 5.5 kg CO₂/kg · Typical Recycled Content 65%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

83 kN·m/kg
68 kN·m/kg

Specific Stiffness (E / density)

24.4 MN·m/kg
24.1 MN·m/kg

Modulus of Resilience

525 kJ/m³
162 kJ/m³

Thermal Diffusivity

4.1 mm²/s
3.8 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 scale303SUS316J1L

Manufacturing and finishing

Capability303SUS316J1L
CNC machiningYes—
Default conditionCold Drawn—
Relative cost$$$ Premium$$$ Premium
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 SUS316J1L — frequently asked

Is 303 stronger than SUS316J1L?

Yes. 303 has a typical yield strength of 450 MPa (65.3 ksi) against 250 MPa (36.3 ksi) for SUS316J1L — about 80% more. Tensile strength is 655 MPa (95 ksi) vs 545 MPa (79 ksi).

Which is cheaper, 303 or SUS316J1L?

Both sit in the same relative cost tier ($$$, premium); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, 303 or SUS316J1L?

303. Its machinability rates very good (72/100) against fair (35/100) for SUS316J1L; for welding the order is SUS316J1L first (excellent, 88/100) then 303 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 303 and SUS316J1L 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.