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Stainless Steel 430 vs S43940

Stainless Steel · grade comparison

Stainless Steel 430 and S43940 are both stainless steel grades. Both yield at about 310 MPa — strength does not separate them. S43940 runs hotter in service (900°C vs 815°C continuous). On the shop floor, S43940 welds better (excellent vs good) and S43940 forms better (very good vs good).

S43940Choose it when the part sees heat, or when it will be welded.

430 vs S43940: properties

430S43940

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

200 GPa29 Msi
210 GPa30.5 Msi

Shear Modulus

77 GPa11.2 Msi
80 GPa11.6 Msi

Poisson's Ratio

0.28
0.29

Tensile Strength (Ultimate)

500 MPa72.5 ksi
480 MPa69.6 ksi

Yield Strength (0.2% offset)

310 MPa45 ksi
300 MPa43.5 ksi

Elongation at Break

30%
32%

Shear Strength

350 MPa50.8 ksi
330 MPa47.9 ksi

Fatigue Strength (Endurance Limit)

240 MPa34.8 ksi
260 MPa37.7 ksi

Fracture Toughness (K_IC)

70 MPa·√m63.7 ksi·√in
—

Charpy V-Notch Impact (RT)

25 J18.4 ft·lbf
60 J44.3 ft·lbf

Hardness, Rockwell B

82 HRB
80 HRB

Compressive Strength

—
300 MPa43.5 ksi

Same in both: Bulk Modulus 160 GPa23.2 Msi · Reduction in Area 65% · Hardness, Brinell 155 HB · Hardness, Vickers 160 HV

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,425°C2,597 °F
1,450°C2,642 °F

Same in both: Density 7.7 g/cm³0.28 lb/in³ · Liquidus Temperature 1,510°C2,750 °F

Thermal

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

Thermal Conductivity

26 W/m·K15 BTU/hr·ft·°F
25 W/m·K14.4 BTU/hr·ft·°F

Latent Heat of Fusion

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

Max Service Temperature (continuous)

815°C1,499 °F
900°C1,652 °F

Min Service Temperature

-30°C-22 °F
-40°C-40 °F

Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 10.4 µm/m·K5.8 µin/in·°F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 2.9 % IACS · Electrical Resistivity 6×10⁻⁷ Ω·m23.6 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

55 / 100
47 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.25 V

Manufacturability

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

Machinability Rating (AISI 1212 = 100 %)

54%
55%

Weldability

60 / 100
88 / 100

Formability (cold)

65 / 100
78 / 100

Brazeability / Solderability

60 / 100
70 / 100

Polishability

80 / 100
70 / 100

Same in both: Machinability 50 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

40 MJ/kg17,197 BTU/lb
48 MJ/kg20,636 BTU/lb

Embodied Carbon (primary production)

3.8 kg CO₂/kg
3.2 kg CO₂/kg

Embodied Water

80 L/kg9.6 gal/lb
110 L/kg13.2 gal/lb

Same in both: Typical Recycled Content 70%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

65 kN·m/kg
62 kN·m/kg

Specific Stiffness (E / density)

26 MN·m/kg
27.3 MN·m/kg

Modulus of Resilience

240 kJ/m³
214 kJ/m³

Thermal Diffusivity

7.3 mm²/s
7.1 mm²/s

Thermal Shock Resistance Index

6
5

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 scale430S43940

Manufacturing and finishing

Capability430S43940
CNC machiningYes—
Sheet metalYes—
Default conditionAnnealed—
Relative cost$$ Standard$$ Standard
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.

430 vs S43940 — frequently asked

What is the difference between 430 and S43940?

Stainless Steel 430 and S43940 are both stainless steel grades. Both yield at about 310 MPa — strength does not separate them. S43940 runs hotter in service (900°C vs 815°C continuous).

Which is cheaper, 430 or S43940?

Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which welds better, 430 or S43940?

S43940. Its weldability rates excellent (88/100) against good (60/100) for 430.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 430 and S43940 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.