FabDigitFabDigit

Stainless Steel ER309 vs ER316

Stainless Steel · grade comparison

Stainless Steel ER309 and ER316 are both stainless steel grades. Both yield at about 400 MPa — strength does not separate them. ER309 runs hotter in service (1,000°C vs 760°C continuous).

ER309Choose it when the part sees heat.

ER309 vs ER316: properties

ER309ER316

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

196 GPa28.4 Msi
193 GPa28 Msi

Shear Modulus

76 GPa11 Msi
77 GPa11.2 Msi

Bulk Modulus

145 GPa21 Msi
140 GPa20.3 Msi

Poisson's Ratio

0.28
0.3

Tensile Strength (Ultimate)

600 MPa87 ksi
590 MPa85.6 ksi

Yield Strength (0.2% offset)

400 MPa58 ksi
420 MPa60.9 ksi

Reduction in Area

50%
45%

Compressive Strength

400 MPa58 ksi
420 MPa60.9 ksi

Shear Strength

390 MPa56.6 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

240 MPa34.8 ksi
235 MPa34.1 ksi

Charpy V-Notch Impact (RT)

75 J55.3 ft·lbf
95 J70.1 ft·lbf

Hardness, Brinell

180 HB
185 HB

Hardness, Vickers

190 HV
195 HV

Same in both: Elongation at Break 38% · Fracture Toughness (K_IC) 140 MPa·√m127 ksi·√in · Hardness, Rockwell B 89 HRB

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,400°C2,552 °F
1,385°C2,525 °F

Liquidus Temperature

1,450°C2,642 °F
1,425°C2,597 °F

Thermal

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

Thermal Conductivity

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

Thermal Expansion (CTE, 20–100 °C)

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

Max Service Temperature (continuous)

1,000°C1,832 °F
760°C1,400 °F

Same in both: Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature -100°C-148 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

2.2 % IACS
2.3 % IACS

Electrical Resistivity

7.8×10⁻⁷ Ω·m30.7 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

72 / 100
70 / 100

Manufacturability

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

Machinability

34 / 100
35 / 100

Machinability Rating (AISI 1212 = 100 %)

38%
32%

Weldability

92 / 100
90 / 100

Formability (cold)

60 / 100
55 / 100

Brazeability / Solderability

55 / 100
60 / 100

Polishability

65 / 100
70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

62 MJ/kg26,655 BTU/lb
75 MJ/kg32,244 BTU/lb

Typical Recycled Content

60%
55%

Same in both: Embodied Carbon (primary production) 5.2 kg CO₂/kg · Embodied Water 130 L/kg15.6 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

76 kN·m/kg
74 kN·m/kg

Specific Stiffness (E / density)

24.8 MN·m/kg
24.2 MN·m/kg

Modulus of Resilience

408 kJ/m³
457 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 scaleER309ER316

Manufacturing and finishing

CapabilityER309ER316
Default condition——
Relative cost$$$ Premium$$$ Premium
Min. machined wall——
Best machined surface——

Both take the same 7 finishes: Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Pickling, Plasma Spray, Silver Plating.

ER309 vs ER316 — frequently asked

What is the difference between ER309 and ER316?

Stainless Steel ER309 and ER316 are both stainless steel grades. Both yield at about 400 MPa — strength does not separate them. ER309 runs hotter in service (1,000°C vs 760°C continuous).

Which is cheaper, ER309 or ER316?

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.

When should I choose ER309 over ER316?

Pick ER309 when the part sees heat.

Ready to make it?

Upload a CAD file and FabDigit prices the part in ER309 and ER316 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.