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Stainless Steel 1.4122 vs 420

Stainless Steel · grade comparison

Stainless Steel 1.4122 and 420 are both stainless steel grades. 1.4122 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 780 MPa (113 ksi) vs 690 MPa (100 ksi). In exchange, 420 is the more ductile: elongation 22% versus 18% for 1.4122, and 1.4122 is harder (240 HB vs 200 HB). 1.4122 is stiffer (216 GPa vs 200 GPa) and 420 runs hotter in service (650°C vs 400°C continuous).

1.4122Choose it when strength drives the design.

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

1.4122 vs 420: properties

1.4122420

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

216 GPa31.3 Msi
200 GPa29 Msi

Shear Modulus

83 GPa12 Msi
78 GPa11.3 Msi

Bulk Modulus

163 GPa23.6 Msi
160 GPa23.2 Msi

Tensile Strength (Ultimate)

780 MPa113 ksi
690 MPa100 ksi

Yield Strength (0.2% offset)

460 MPa66.7 ksi
360 MPa52.2 ksi

Elongation at Break

18%
22%

Reduction in Area

45%
55%

Compressive Strength

470 MPa68.2 ksi
380 MPa55.1 ksi

Shear Strength

470 MPa68.2 ksi
420 MPa60.9 ksi

Fatigue Strength (Endurance Limit)

340 MPa49.3 ksi
350 MPa50.8 ksi

Charpy V-Notch Impact (RT)

30 J22.1 ft·lbf
25 J18.4 ft·lbf

Hardness, Brinell

240 HB
200 HB

Hardness, Rockwell C

22 HRC
—

Hardness, Vickers

250 HV
210 HV

Fracture Toughness (K_IC)

—
60 MPa·√m54.6 ksi·√in

Hardness, Rockwell B

—
93 HRB

Same in both: Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,420°C2,588 °F
1,454°C2,649 °F

Liquidus Temperature

1,490°C2,714 °F
1,510°C2,750 °F

Thermal

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

Thermal Conductivity

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

Thermal Expansion (CTE, 20–100 °C)

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

Latent Heat of Fusion

270 J/g116 BTU/lb
260 J/g112 BTU/lb

Max Service Temperature (continuous)

400°C752 °F
650°C1,202 °F

Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Min Service Temperature -30°C-22 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

2.9 % IACS
3.1 % IACS

Electrical Resistivity

6×10⁻⁷ Ω·m23.6 µΩ·in
5.5×10⁻⁷ Ω·m21.7 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

32 / 100
40 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.3 V

Manufacturability

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

Weldability

22 / 100
25 / 100

Formability (cold)

30 / 100
40 / 100

Brazeability / Solderability

45 / 100
40 / 100

Polishability

75 / 100
85 / 100

Castability

—
45 / 100

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

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

4.8 kg CO₂/kg
3.5 kg CO₂/kg

Embodied Water

110 L/kg13.2 gal/lb
250 L/kg30 gal/lb

Typical Recycled Content

50%
45%

Same in both: Embodied Energy (primary production) 55 MJ/kg23,646 BTU/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

101 kN·m/kg
89 kN·m/kg

Specific Stiffness (E / density)

28.1 MN·m/kg
25.8 MN·m/kg

Modulus of Resilience

490 kJ/m³
324 kJ/m³

Thermal Diffusivity

8.5 mm²/s
7 mm²/s

Thermal Shock Resistance Index

10
8

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 scale4201.4122

Manufacturing and finishing

Capability1.4122420
CNC machining—Yes
Default condition—Annealed
Relative cost$$$ Premium$$$ Premium
Min. machined wall—0.8 mm
Best machined surface—Ra 1.6 µm
AlCrN—Yes
AlTiN—Yes
Black Oxide—Yes
CVD Al2O3—Yes
CVD TiCN—Yes
CVD TiN—Yes
Cerakote—Yes
Chrome Plating—Yes
CrN—Yes
DLC—Yes
Electropolishing—Yes
HVOF Coating—Yes
MoS2—Yes
Multilayer CVD—Yes
Nickel Plating—Yes
PTFE Coating—Yes
Painting—Yes
Passivation (Stainless Steel)—Yes

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

1.4122 vs 420 — frequently asked

Is 1.4122 stronger than 420?

Yes. 1.4122 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 780 MPa (113 ksi) vs 690 MPa (100 ksi).

Which is cheaper, 1.4122 or 420?

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.

When should I choose 1.4122 over 420?

Pick 1.4122 when strength drives the design. Pick 420 when the part is bent, formed or impact-loaded, or when the part sees heat.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 1.4122 and 420 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.