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Stainless Steel 20Cb-3 vs Haynes 556

Stainless Steel · grade comparison

Stainless Steel 20Cb-3 and Haynes 556 are both stainless steel grades. Haynes 556 is the stronger of the two: yield strength 410 MPa (59.5 ksi) against 345 MPa (50 ksi) for 20Cb-3, about 19% more; tensile strength follows at 815 MPa (118 ksi) vs 620 MPa (89.9 ksi). Haynes 556 is the more ductile: elongation 48% versus 42% for 20Cb-3, and Haynes 556 is harder (200 HB vs 160 HB). Haynes 556 is stiffer (205 GPa vs 193 GPa) and Haynes 556 runs hotter in service (1,100°C vs 500°C continuous). On the shop floor, 20Cb-3 machines more easily (33 vs 20 out of 100) and 20Cb-3 sits in a lower cost tier (premium, $$$) than Haynes 556 (high, $$$$).

20Cb-3Choose it when the part is machined in volume, or when cost is the deciding factor.

Haynes 556Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

20Cb-3 vs Haynes 556: properties

20Cb-3Haynes 556

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

193 GPa28 Msi
205 GPa29.7 Msi

Shear Modulus

74 GPa10.7 Msi
79 GPa11.5 Msi

Bulk Modulus

161 GPa23.4 Msi
180 GPa26.1 Msi

Poisson's Ratio

0.3
0.31

Tensile Strength (Ultimate)

620 MPa89.9 ksi
815 MPa118 ksi

Yield Strength (0.2% offset)

345 MPa50 ksi
410 MPa59.5 ksi

Elongation at Break

42%
48%

Reduction in Area

60%
50%

Shear Strength

400 MPa58 ksi
520 MPa75.4 ksi

Fatigue Strength (Endurance Limit)

275 MPa39.9 ksi
350 MPa50.8 ksi

Charpy V-Notch Impact (RT)

200 J148 ft·lbf
120 J88.5 ft·lbf

Hardness, Brinell

160 HB
200 HB

Hardness, Rockwell B

83 HRB
92 HRB

Hardness, Vickers

170 HV
—

Physical

Density and transition temperatures.

Density

8.08 g/cm³0.29 lb/in³
8.23 g/cm³0.3 lb/in³

Melting Point (Solidus)

1,425°C2,597 °F
1,320°C2,408 °F

Liquidus Temperature

1,445°C2,633 °F
1,355°C2,471 °F

Thermal

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

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

14.8 µm/m·K8.2 µin/in·°F
14.1 µm/m·K7.8 µin/in·°F

Max Service Temperature (continuous)

500°C932 °F
1,100°C2,012 °F

Same in both: Thermal Conductivity 12.6 W/m·K7.3 BTU/hr·ft·°F · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

1.6 % IACS
1.8 % IACS

Electrical Resistivity

1.08×10⁻⁶ Ω·m42.5 µΩ·in
9.5×10⁻⁷ Ω·m37.4 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.1 V
—

Corrosion Resistance

72 / 100
78 / 100

Manufacturability

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

Machinability

33 / 100
20 / 100

Machinability Rating (AISI 1212 = 100 %)

40%
12%

Weldability

75 / 100
72 / 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
240 MJ/kg103,182 BTU/lb

Embodied Carbon (primary production)

7.5 kg CO₂/kg
17 kg CO₂/kg

Embodied Water

150 L/kg18 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
99 kN·m/kg

Specific Stiffness (E / density)

23.9 MN·m/kg
24.9 MN·m/kg

Modulus of Resilience

308 kJ/m³
410 kJ/m³

Thermal Diffusivity

3.1 mm²/s
3.4 mm²/s

Thermal Shock Resistance Index

3
4

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 scaleHaynes 55620Cb-3

Manufacturing and finishing

Capability20Cb-3Haynes 556
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 Haynes 556 — frequently asked

Is Haynes 556 stronger than 20Cb-3?

Yes. Haynes 556 has a typical yield strength of 410 MPa (59.5 ksi) against 345 MPa (50 ksi) for 20Cb-3 — about 19% more. Tensile strength is 815 MPa (118 ksi) vs 620 MPa (89.9 ksi).

Which is cheaper, 20Cb-3 or Haynes 556?

20Cb-3 is the lower-cost material: it sits in the premium tier ($$$) while Haynes 556 is high ($$$$). 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 Haynes 556?

20Cb-3, by a small margin. Both rate poor for machinability — 33/100 against 20/100 for Haynes 556.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 20Cb-3 and Haynes 556 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.