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Stainless Steel 420 vs S42300

Stainless Steel · grade comparison

Stainless Steel 420 and S42300 are both stainless steel grades. S42300 is the stronger of the two: yield strength 850 MPa (123 ksi) against 360 MPa (52.2 ksi) for 420, about 136% more; tensile strength follows at 1,000 MPa (145 ksi) vs 690 MPa (100 ksi). In exchange, 420 is the more ductile: elongation 22% versus 17% for S42300, and S42300 is harder (293 HB vs 200 HB). 420 runs hotter in service (650°C vs 540°C continuous).

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

S42300Choose it when strength drives the design.

420 vs S42300: properties

420S42300

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

690 MPa100 ksi
1,000 MPa145 ksi

Yield Strength (0.2% offset)

360 MPa52.2 ksi
850 MPa123 ksi

Elongation at Break

22%
17%

Compressive Strength

380 MPa55.1 ksi
880 MPa128 ksi

Shear Strength

420 MPa60.9 ksi
620 MPa89.9 ksi

Fatigue Strength (Endurance Limit)

350 MPa50.8 ksi
470 MPa68.2 ksi

Fracture Toughness (K_IC)

60 MPa·√m54.6 ksi·√in
80 MPa·√m72.8 ksi·√in

Charpy V-Notch Impact (RT)

25 J18.4 ft·lbf
27 J19.9 ft·lbf

Hardness, Brinell

200 HB
293 HB

Hardness, Rockwell B

93 HRB
—

Hardness, Vickers

210 HV
305 HV

Hardness, Rockwell C

—
30 HRC

Same in both: Elastic (Young's) Modulus 200 GPa29 Msi · Shear Modulus 78 GPa11.3 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Reduction in Area 55%

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,454°C2,649 °F
1,425°C2,597 °F

Same in both: Liquidus Temperature 1,510°C2,750 °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
24 W/m·K13.9 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

10.3 µm/m·K5.7 µin/in·°F
11.2 µm/m·K6.2 µin/in·°F

Latent Heat of Fusion

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

Max Service Temperature (continuous)

650°C1,202 °F
540°C1,004 °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

3.1 % IACS
2.9 % IACS

Electrical Resistivity

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

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.3 V
-0.32 V

Same in both: Corrosion Resistance 40 / 100

Manufacturability

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

Machinability

45 / 100
38 / 100

Machinability Rating (AISI 1212 = 100 %)

45%
40%

Formability (cold)

40 / 100
20 / 100

Castability

45 / 100
—

Polishability

85 / 100
72 / 100

Same in both: Weldability 25 / 100 · Brazeability / Solderability 40 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

55 MJ/kg23,646 BTU/lb
53 MJ/kg22,786 BTU/lb

Embodied Carbon (primary production)

3.5 kg CO₂/kg
4.8 kg CO₂/kg

Embodied Water

250 L/kg30 gal/lb
130 L/kg15.6 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
129 kN·m/kg

Modulus of Resilience

324 kJ/m³
1,806 kJ/m³

Thermal Diffusivity

7 mm²/s
6.7 mm²/s

Thermal Shock Resistance Index

8
11

Same in both: Specific Stiffness (E / density) 25.8 MN·m/kg

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 scale420S42300

Manufacturing and finishing

Capability420S42300
CNC machiningYes—
Default conditionAnnealed—
Relative cost$$$ Premium$$$ Premium
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.

420 vs S42300 — frequently asked

Is S42300 stronger than 420?

Yes. S42300 has a typical yield strength of 850 MPa (123 ksi) against 360 MPa (52.2 ksi) for 420 — about 136% more. Tensile strength is 1,000 MPa (145 ksi) vs 690 MPa (100 ksi).

Which is cheaper, 420 or S42300?

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, 420 or S42300?

420, by a small margin. Both rate fair for machinability — 45/100 against 38/100 for S42300.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 420 and S42300 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.