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Stainless Steel 420 vs 420C

Stainless Steel · grade comparison

Stainless Steel 420 and 420C are both stainless steel grades, both high strength ss. 420C is the stronger of the two: yield strength 460 MPa (66.7 ksi) against 360 MPa (52.2 ksi) for 420, about 28% more; tensile strength follows at 760 MPa (110 ksi) vs 690 MPa (100 ksi). In exchange, 420 is the more ductile: elongation 22% versus 17% for 420C, and 420C is harder (220 HB vs 200 HB). 420C is stiffer (215 GPa vs 200 GPa) and 420 runs hotter in service (650°C vs 400°C continuous).

420Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

420CChoose it when strength drives the design.

420 vs 420C: properties

420420C

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

200 GPa29 Msi
215 GPa31.2 Msi

Shear Modulus

78 GPa11.3 Msi
83 GPa12 Msi

Poisson's Ratio

0.29
0.28

Tensile Strength (Ultimate)

690 MPa100 ksi
760 MPa110 ksi

Yield Strength (0.2% offset)

360 MPa52.2 ksi
460 MPa66.7 ksi

Elongation at Break

22%
17%

Reduction in Area

55%
40%

Compressive Strength

380 MPa55.1 ksi
470 MPa68.2 ksi

Shear Strength

420 MPa60.9 ksi
460 MPa66.7 ksi

Fracture Toughness (K_IC)

60 MPa·√m54.6 ksi·√in
55 MPa·√m50.1 ksi·√in

Hardness, Brinell

200 HB
220 HB

Hardness, Rockwell B

93 HRB
97 HRB

Hardness, Vickers

210 HV
230 HV

Hardness, Rockwell C

—
20 HRC

Same in both: Bulk Modulus 160 GPa23.2 Msi · Fatigue Strength (Endurance Limit) 350 MPa50.8 ksi · Charpy V-Notch Impact (RT) 25 J18.4 ft·lbf

Physical

Density and transition temperatures.

Density

7.75 g/cm³0.28 lb/in³
7.7 g/cm³0.28 lb/in³

Melting Point (Solidus)

1,454°C2,649 °F
1,425°C2,597 °F

Liquidus Temperature

1,510°C2,750 °F
1,500°C2,732 °F

Thermal

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

Thermal Conductivity

24.9 W/m·K14.4 BTU/hr·ft·°F
30 W/m·K17.3 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

10.3 µm/m·K5.7 µin/in·°F
10.5 µm/m·K5.8 µin/in·°F

Max Service Temperature (continuous)

650°C1,202 °F
400°C752 °F

Min Service Temperature

-30°C-22 °F
-20°C-4 °F

Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Latent Heat of Fusion 260 J/g112 BTU/lb

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 3.1 % IACS · Electrical Resistivity 5.5×10⁻⁷ Ω·m21.7 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.3 V
-0.35 V

Corrosion Resistance

40 / 100
42 / 100

Manufacturability

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

Weldability

25 / 100
20 / 100

Formability (cold)

40 / 100
30 / 100

Castability

45 / 100
40 / 100

Brazeability / Solderability

40 / 100
45 / 100

Polishability

85 / 100
78 / 100

Same in both: Machinability 45 / 100 · Machinability Rating (AISI 1212 = 100 %) 45%

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

55 MJ/kg23,646 BTU/lb
50 MJ/kg21,496 BTU/lb

Embodied Carbon (primary production)

3.5 kg CO₂/kg
3.4 kg CO₂/kg

Embodied Water

250 L/kg30 gal/lb
90 L/kg10.8 gal/lb

Same in both: Typical Recycled Content 45%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

89 kN·m/kg
99 kN·m/kg

Specific Stiffness (E / density)

25.8 MN·m/kg
27.9 MN·m/kg

Modulus of Resilience

324 kJ/m³
492 kJ/m³

Thermal Diffusivity

7 mm²/s
8.5 mm²/s

Thermal Shock Resistance Index

8
10

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 scale420420C

Manufacturing and finishing

Capability420420C
Default conditionAnnealed—
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. 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.

420 vs 420C — frequently asked

Is 420C stronger than 420?

Yes. 420C has a typical yield strength of 460 MPa (66.7 ksi) against 360 MPa (52.2 ksi) for 420 — about 28% more. Tensile strength is 760 MPa (110 ksi) vs 690 MPa (100 ksi).

Which is cheaper, 420 or 420C?

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 welds better, 420 or 420C?

420. Its weldability rates poor (25/100) against poor (20/100) for 420C.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 420 and 420C 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.