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Stainless Steel 20Cb-3 vs S35125

Stainless Steel · grade comparison

Stainless Steel 20Cb-3 and S35125 are both stainless steel grades. 20Cb-3 is the stronger of the two: yield strength 345 MPa (50 ksi) against 270 MPa (39.2 ksi) for S35125, about 28% more. S35125 runs hotter in service (1,100°C vs 500°C continuous). On the shop floor, 20Cb-3 forms better (very good vs good) and 20Cb-3 sits in a lower cost tier (premium, $$$) than S35125 (high, $$$$).

20Cb-3Choose it when strength drives the design, or when cost is the deciding factor.

S35125Choose it when the part sees heat.

20Cb-3 vs S35125: properties

20Cb-3S35125

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
160 GPa23.2 Msi

Tensile Strength (Ultimate)

620 MPa89.9 ksi
600 MPa87 ksi

Yield Strength (0.2% offset)

345 MPa50 ksi
270 MPa39.2 ksi

Elongation at Break

42%
45%

Reduction in Area

60%
55%

Fatigue Strength (Endurance Limit)

275 MPa39.9 ksi
250 MPa36.3 ksi

Charpy V-Notch Impact (RT)

200 J148 ft·lbf
130 J95.9 ft·lbf

Hardness, Brinell

160 HB
165 HB

Hardness, Rockwell B

83 HRB
85 HRB

Hardness, Vickers

170 HV
175 HV

Same in both: Poisson's Ratio 0.3 · Shear Strength 400 MPa58 ksi

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,425°C2,597 °F
1,330°C2,426 °F

Liquidus Temperature

1,445°C2,633 °F
1,385°C2,525 °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
460 J/kg·K0.11 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

14.8 µm/m·K8.2 µin/in·°F
15 µm/m·K8.3 µin/in·°F

Max Service Temperature (continuous)

500°C932 °F
1,100°C2,012 °F

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

Electrical

Conductivity and insulation.

Electrical Conductivity

1.6 % IACS
1.7 % IACS

Electrical Resistivity

1.08×10⁻⁶ Ω·m42.5 µΩ·in
1×10⁻⁶ Ω·m39.4 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.1 V
—

Same in both: Corrosion Resistance 72 / 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%
28%

Weldability

75 / 100
70 / 100

Formability (cold)

70 / 100
60 / 100

Polishability

75 / 100
65 / 100

Same in both: Brazeability / Solderability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

110 MJ/kg47,292 BTU/lb
90 MJ/kg38,693 BTU/lb

Embodied Carbon (primary production)

7.5 kg CO₂/kg
6.8 kg CO₂/kg

Embodied Water

150 L/kg18 gal/lb
250 L/kg30 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
75 kN·m/kg

Specific Stiffness (E / density)

23.9 MN·m/kg
24.5 MN·m/kg

Modulus of Resilience

308 kJ/m³
187 kJ/m³

Thermal Shock Resistance Index

3
2

Same in both: Thermal Diffusivity 3.1 mm²/s

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 scaleS3512520Cb-3

Manufacturing and finishing

Capability20Cb-3S35125
CNC machiningYes—
Sheet metalYes—
Default conditionSolution Annealed—
Relative cost$$$ Premium$$$$ High
Min. machined wall0.8 mm—
Best machined surfaceRa 1.6 µm—
AlCrNYes—
AlTiNYes—
Black OxideYes—
CVD Al2O3Yes—
CVD TiCNYes—
CVD TiNYes—
CerakoteYes—
Chrome PlatingYes—
CrNYes—
DLCYes—
ElectropolishingYes—
HVOF CoatingYes—
MoS2Yes—
Multilayer CVDYes—
Nickel PlatingYes—
PTFE CoatingYes—
PaintingYes—
Passivation (Stainless Steel)Yes—

They share 7 finishes: Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Pickling, Plasma Spray, Silver Plating.

20Cb-3 vs S35125 — frequently asked

Is 20Cb-3 stronger than S35125?

Yes. 20Cb-3 has a typical yield strength of 345 MPa (50 ksi) against 270 MPa (39.2 ksi) for S35125 — about 28% more. Tensile strength is 620 MPa (89.9 ksi) vs 600 MPa (87 ksi).

Which is cheaper, 20Cb-3 or S35125?

20Cb-3 is the lower-cost material: it sits in the premium tier ($$$) while S35125 is high ($$$$). 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, 20Cb-3 or S35125?

20Cb-3, by a small margin. Both rate poor for machinability — 33/100 against 25/100 for S35125; for welding the order is 20Cb-3 first (very good, 75/100) then S35125 (very good, 70/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 20Cb-3 and S35125 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.