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Stainless Steel ER307 vs ER308

Stainless Steel · grade comparison

Stainless Steel ER307 and ER308 are both stainless steel grades. Both yield at about 400 MPa — strength does not separate them. ER307 runs hotter in service (850°C vs 760°C continuous). On the shop floor, ER307 forms better (65 vs 55 out of 100).

ER307Choose it when the part sees heat.

ER307 vs ER308: properties

ER307ER308

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

196 GPa28.4 Msi
195 GPa28.3 Msi

Shear Modulus

76 GPa11 Msi
77 GPa11.2 Msi

Bulk Modulus

160 GPa23.2 Msi
145 GPa21 Msi

Poisson's Ratio

0.28
0.3

Tensile Strength (Ultimate)

620 MPa89.9 ksi
600 MPa87 ksi

Elongation at Break

38%
40%

Reduction in Area

50%
55%

Compressive Strength

410 MPa59.5 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

250 MPa36.3 ksi
240 MPa34.8 ksi

Fracture Toughness (K_IC)

110 MPa·√m100 ksi·√in
150 MPa·√m137 ksi·√in

Charpy V-Notch Impact (RT)

70 J51.6 ft·lbf
90 J66.4 ft·lbf

Hardness, Brinell

190 HB
185 HB

Hardness, Rockwell B

92 HRB
90 HRB

Hardness, Vickers

200 HV
195 HV

Same in both: Yield Strength (0.2% offset) 400 MPa58 ksi · Shear Strength 400 MPa58 ksi

Physical

Density and transition temperatures.

Same in both: Density 7.9 g/cm³0.29 lb/in³ · Melting Point (Solidus) 1,400°C2,552 °F · Liquidus Temperature 1,450°C2,642 °F

Thermal

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

Thermal Conductivity

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

Thermal Expansion (CTE, 20–100 °C)

17.5 µm/m·K9.7 µin/in·°F
16.9 µm/m·K9.4 µin/in·°F

Latent Heat of Fusion

270 J/g116 BTU/lb
280 J/g120 BTU/lb

Max Service Temperature (continuous)

850°C1,562 °F
760°C1,400 °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

2.2 % IACS
2.4 % IACS

Electrical Resistivity

8×10⁻⁷ Ω·m31.5 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)

-0.05 V
-0.08 V

Corrosion Resistance

58 / 100
65 / 100

Manufacturability

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

Machinability

30 / 100
38 / 100

Machinability Rating (AISI 1212 = 100 %)

35%
45%

Weldability

92 / 100
95 / 100

Formability (cold)

65 / 100
55 / 100

Brazeability / Solderability

55 / 100
60 / 100

Polishability

60 / 100
70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

56 MJ/kg24,076 BTU/lb
57 MJ/kg24,506 BTU/lb

Embodied Carbon (primary production)

4.6 kg CO₂/kg
5 kg CO₂/kg

Embodied Water

120 L/kg14.4 gal/lb
130 L/kg15.6 gal/lb

Typical Recycled Content

60%
45%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

78 kN·m/kg
76 kN·m/kg

Specific Stiffness (E / density)

24.8 MN·m/kg
24.7 MN·m/kg

Modulus of Resilience

408 kJ/m³
410 kJ/m³

Thermal Diffusivity

3.8 mm²/s
3.9 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 scaleER308ER307

Manufacturing and finishing

CapabilityER307ER308
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.

ER307 vs ER308 — frequently asked

What is the difference between ER307 and ER308?

Stainless Steel ER307 and ER308 are both stainless steel grades. Both yield at about 400 MPa — strength does not separate them. ER307 runs hotter in service (850°C vs 760°C continuous).

Which is cheaper, ER307 or ER308?

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, ER307 or ER308?

ER308. Its machinability rates fair (38/100) against poor (30/100) for ER307.

Ready to make it?

Upload a CAD file and FabDigit prices the part in ER307 and ER308 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.