FabDigitFabDigit

Steel 8620 vs 9310

Steel · grade comparison

Steel 8620 and 9310 are both steel grades. 9310 is the stronger of the two: yield strength 600 MPa (87 ksi) against 385 MPa (55.8 ksi) for 8620, about 56% more; tensile strength follows at 950 MPa (138 ksi) vs 635 MPa (92.1 ksi). In exchange, 8620 is the more ductile: elongation 28% versus 15% for 9310, and 9310 is harder (270 HB vs 183 HB). 8620 conducts heat better (46.6 W/m·K vs 34 W/m·K). On the shop floor, 8620 machines more easily (good vs fair), 8620 welds better (good vs fair), and 8620 sits in a lower cost tier (standard, $$) than 9310 (premium, $$$).

8620Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

9310Choose it when strength drives the design.

8620 vs 9310: properties

86209310

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

635 MPa92.1 ksi
950 MPa138 ksi

Yield Strength (0.2% offset)

385 MPa55.8 ksi
600 MPa87 ksi

Elongation at Break

28%
15%

Reduction in Area

60%
45%

Shear Strength

390 MPa56.6 ksi
590 MPa85.6 ksi

Fatigue Strength (Endurance Limit)

295 MPa42.8 ksi
430 MPa62.4 ksi

Fracture Toughness (K_IC)

85 MPa·√m77.4 ksi·√in
95 MPa·√m86.5 ksi·√in

Charpy V-Notch Impact (RT)

90 J66.4 ft·lbf
60 J44.3 ft·lbf

Hardness, Brinell

183 HB
270 HB

Hardness, Rockwell B

90 HRB
98 HRB

Compressive Strength

—
620 MPa89.9 ksi

Hardness, Rockwell C

—
27 HRC

Hardness, Vickers

—
284 HV

Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,425°C2,597 °F
1,420°C2,588 °F

Liquidus Temperature

1,505°C2,741 °F
1,490°C2,714 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³

Thermal

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

Thermal Conductivity

46.6 W/m·K26.9 BTU/hr·ft·°F
34 W/m·K19.6 BTU/hr·ft·°F

Min Service Temperature

-40°C-40 °F
-90°C-130 °F

Same in both: Specific Heat Capacity 475 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.6 µm/m·K6.4 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Max Service Temperature (continuous) 400°C752 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

8 % IACS
6.6 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
2.6×10⁻⁷ Ω·m10.2 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

11 / 100
14 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V

Manufacturability

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

Machinability

62 / 100
40 / 100

Machinability Rating (AISI 1212 = 100 %)

65%
40%

Weldability

60 / 100
38 / 100

Formability (cold)

55 / 100
35 / 100

Brazeability / Solderability

65 / 100
55 / 100

Polishability

70 / 100
65 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

30 MJ/kg12,898 BTU/lb
34 MJ/kg14,617 BTU/lb

Embodied Carbon (primary production)

2.1 kg CO₂/kg
2.5 kg CO₂/kg

Typical Recycled Content

30%
25%

Same in both: Embodied Water 60 L/kg7.2 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

81 kN·m/kg
121 kN·m/kg

Modulus of Resilience

362 kJ/m³
878 kJ/m³

Thermal Diffusivity

12.5 mm²/s
9.1 mm²/s

Thermal Shock Resistance Index

12
14

Same in both: Specific Stiffness (E / density) 26.1 MN·m/kg

Strength versus weight

Yield strength against density for every steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scale86209310

Manufacturing and finishing

Capability86209310
Default conditionHRHR
Relative cost$$ Standard$$$ Premium
Min. machined wall0.8 mm0.8 mm
Best machined surfaceRa 1.6 µmRa 1.6 µm

Both are offered for CNC machining and Sheet metal. Both take the same 38 finishes: AlCrN, AlTiN, Black Oxide, CVD Al2O3, CVD TiCN, CVD TiN, Cerakote, Chrome Plating, Copper Plating, CrN, DLC, E-Coating and 26 more.

8620 vs 9310 — frequently asked

Is 9310 stronger than 8620?

Yes. 9310 has a typical yield strength of 600 MPa (87 ksi) against 385 MPa (55.8 ksi) for 8620 — about 56% more. Tensile strength is 950 MPa (138 ksi) vs 635 MPa (92.1 ksi).

Which is cheaper, 8620 or 9310?

8620 is the lower-cost material: it sits in the standard tier ($$) while 9310 is premium ($$$). 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, 8620 or 9310?

8620. Its machinability rates good (62/100) against fair (40/100) for 9310; for welding the order is 8620 first (good, 60/100) then 9310 (fair, 38/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 8620 and 9310 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.