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Steel 17CrNiMo6 vs 8620

Steel · grade comparison

Steel 17CrNiMo6 and 8620 are both steel grades, both case hardening steel. 17CrNiMo6 is the stronger of the two: yield strength 430 MPa (62.4 ksi) against 385 MPa (55.8 ksi) for 8620, about 12% more; tensile strength follows at 700 MPa (102 ksi) vs 635 MPa (92.1 ksi). In exchange, 8620 is the more ductile: elongation 28% versus 20% for 17CrNiMo6, and 17CrNiMo6 is harder (200 HB vs 183 HB). 8620 runs hotter in service (400°C vs 300°C continuous) and 8620 conducts heat better (46.6 W/m·K vs 38 W/m·K). On the shop floor, 8620 machines more easily (good vs fair) and 8620 welds better (good vs poor).

17CrNiMo6Choose it when strength drives the design.

8620Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

17CrNiMo6 vs 8620: properties

17CrNiMo68620

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

210 GPa30.5 Msi
205 GPa29.7 Msi

Tensile Strength (Ultimate)

700 MPa102 ksi
635 MPa92.1 ksi

Yield Strength (0.2% offset)

430 MPa62.4 ksi
385 MPa55.8 ksi

Elongation at Break

20%
28%

Reduction in Area

55%
60%

Shear Strength

430 MPa62.4 ksi
390 MPa56.6 ksi

Fatigue Strength (Endurance Limit)

320 MPa46.4 ksi
295 MPa42.8 ksi

Charpy V-Notch Impact (RT)

65 J47.9 ft·lbf
90 J66.4 ft·lbf

Hardness, Brinell

200 HB
183 HB

Hardness, Rockwell B

93 HRB
90 HRB

Hardness, Vickers

210 HV
—

Fracture Toughness (K_IC)

—
85 MPa·√m77.4 ksi·√in

Same in both: 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)

1,420°C2,588 °F
1,425°C2,597 °F

Liquidus Temperature

1,490°C2,714 °F
1,505°C2,741 °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

38 W/m·K22 BTU/hr·ft·°F
46.6 W/m·K26.9 BTU/hr·ft·°F

Specific Heat Capacity

470 J/kg·K0.11 BTU/lb·°F
475 J/kg·K0.11 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

11.5 µm/m·K6.4 µin/in·°F
11.6 µm/m·K6.4 µin/in·°F

Max Service Temperature (continuous)

300°C572 °F
400°C752 °F

Same in both: Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 8 % IACS · Electrical Resistivity 2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

12 / 100
11 / 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

50 / 100
62 / 100

Machinability Rating (AISI 1212 = 100 %)

55%
65%

Weldability

30 / 100
60 / 100

Formability (cold)

40 / 100
55 / 100

Castability

25 / 100
—

Brazeability / Solderability

45 / 100
65 / 100

Polishability

65 / 100
70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

32 MJ/kg13,758 BTU/lb
30 MJ/kg12,898 BTU/lb

Embodied Carbon (primary production)

2.3 kg CO₂/kg
2.1 kg CO₂/kg

Embodied Water

55 L/kg6.6 gal/lb
60 L/kg7.2 gal/lb

Same in both: Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

89 kN·m/kg
81 kN·m/kg

Specific Stiffness (E / density)

26.8 MN·m/kg
26.1 MN·m/kg

Modulus of Resilience

440 kJ/m³
362 kJ/m³

Thermal Diffusivity

10.3 mm²/s
12.5 mm²/s

Thermal Shock Resistance Index

11
12

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 scale862017CrNiMo6

Manufacturing and finishing

Capability17CrNiMo68620
Default conditionAnnealedHR
Relative cost$$ Standard$$ Standard
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.

17CrNiMo6 vs 8620 — frequently asked

Is 17CrNiMo6 stronger than 8620?

Yes. 17CrNiMo6 has a typical yield strength of 430 MPa (62.4 ksi) against 385 MPa (55.8 ksi) for 8620 — about 12% more. Tensile strength is 700 MPa (102 ksi) vs 635 MPa (92.1 ksi).

Which is cheaper, 17CrNiMo6 or 8620?

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

Which is easier to machine, 17CrNiMo6 or 8620?

8620. Its machinability rates good (62/100) against fair (50/100) for 17CrNiMo6; for welding the order is 8620 first (good, 60/100) then 17CrNiMo6 (poor, 30/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 17CrNiMo6 and 8620 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.