FabDigitFabDigit

Stainless Steel 20Cb-3 vs AL-6XN

Stainless Steel · grade comparison

Stainless Steel 20Cb-3 and AL-6XN are both stainless steel grades. AL-6XN is the stronger of the two: yield strength 365 MPa (52.9 ksi) against 345 MPa (50 ksi) for 20Cb-3, about 6% more; tensile strength follows at 745 MPa (108 ksi) vs 620 MPa (89.9 ksi). AL-6XN is harder — 180 HB against 160 HB for 20Cb-3 — which matters for wear surfaces and threads. 20Cb-3 runs hotter in service (500°C vs 425°C continuous) and AL-6XN conducts electricity better (1.9 % IACS vs 1.6 % IACS). On the shop floor, 20Cb-3 forms better (very good vs good).

20Cb-3Choose it when the part sees heat.

AL-6XNChoose it when strength drives the design, or when surface hardness matters.

20Cb-3 vs AL-6XN: properties

20Cb-3AL-6XN

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

193 GPa28 Msi
195 GPa28.3 Msi

Shear Modulus

74 GPa10.7 Msi
75 GPa10.9 Msi

Bulk Modulus

161 GPa23.4 Msi
162 GPa23.5 Msi

Tensile Strength (Ultimate)

620 MPa89.9 ksi
745 MPa108 ksi

Yield Strength (0.2% offset)

345 MPa50 ksi
365 MPa52.9 ksi

Elongation at Break

42%
45%

Reduction in Area

60%
65%

Shear Strength

400 MPa58 ksi
450 MPa65.3 ksi

Fatigue Strength (Endurance Limit)

275 MPa39.9 ksi
340 MPa49.3 ksi

Charpy V-Notch Impact (RT)

200 J148 ft·lbf
250 J184 ft·lbf

Hardness, Brinell

160 HB
180 HB

Hardness, Rockwell B

83 HRB
88 HRB

Hardness, Vickers

170 HV
190 HV

Fracture Toughness (K_IC)

—
200 MPa·√m182 ksi·√in

Same in both: Poisson's Ratio 0.3

Physical

Density and transition temperatures.

Density

8.08 g/cm³0.29 lb/in³
8.06 g/cm³0.29 lb/in³

Melting Point (Solidus)

1,425°C2,597 °F
1,320°C2,408 °F

Liquidus Temperature

1,445°C2,633 °F
1,400°C2,552 °F

Thermal

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

Thermal Conductivity

12.6 W/m·K7.3 BTU/hr·ft·°F
11.5 W/m·K6.6 BTU/hr·ft·°F

Specific Heat Capacity

500 J/kg·K0.12 BTU/lb·°F
456 J/kg·K0.11 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

14.8 µm/m·K8.2 µin/in·°F
15.3 µm/m·K8.5 µin/in·°F

Max Service Temperature (continuous)

500°C932 °F
425°C797 °F

Latent Heat of Fusion

—
280 J/g120 BTU/lb

Same in both: Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

1.6 % IACS
1.9 % IACS

Electrical Resistivity

1.08×10⁻⁶ Ω·m42.5 µΩ·in
8.9×10⁻⁷ Ω·m35 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
88 / 100

Manufacturability

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

Machinability

33 / 100
25 / 100

Machinability Rating (AISI 1212 = 100 %)

40%
25%

Formability (cold)

70 / 100
60 / 100

Brazeability / Solderability

55 / 100
50 / 100

Polishability

75 / 100
80 / 100

Same in both: Weldability 75 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

110 MJ/kg47,292 BTU/lb
85 MJ/kg36,543 BTU/lb

Embodied Carbon (primary production)

7.5 kg CO₂/kg
6 kg CO₂/kg

Embodied Water

150 L/kg18 gal/lb
220 L/kg26.4 gal/lb

Same in both: Typical Recycled Content 40%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

77 kN·m/kg
92 kN·m/kg

Specific Stiffness (E / density)

23.9 MN·m/kg
24.2 MN·m/kg

Modulus of Resilience

308 kJ/m³
342 kJ/m³

Same in both: Thermal Diffusivity 3.1 mm²/s · 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 scale20Cb-3AL-6XN

Manufacturing and finishing

Capability20Cb-3AL-6XN
Default conditionSolution AnnealedSolution Annealed
Relative cost$$$ Premium$$$ 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 32 finishes: AlCrN, AlTiN, Black Oxide, CVD Al2O3, CVD TiCN, CVD TiN, Cerakote, Chrome Plating, CrN, DLC, Electroless Nickel (EN), Electropolishing and 20 more.

20Cb-3 vs AL-6XN — frequently asked

Is AL-6XN stronger than 20Cb-3?

Yes. AL-6XN has a typical yield strength of 365 MPa (52.9 ksi) against 345 MPa (50 ksi) for 20Cb-3 — about 6% more. Tensile strength is 745 MPa (108 ksi) vs 620 MPa (89.9 ksi).

Which is cheaper, 20Cb-3 or AL-6XN?

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, 20Cb-3 or AL-6XN?

20Cb-3, by a small margin. Both rate poor for machinability — 33/100 against 25/100 for AL-6XN.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 20Cb-3 and AL-6XN 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.