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Stainless Steel 430 vs S40975

Stainless Steel · grade comparison

Stainless Steel 430 and S40975 are both stainless steel grades. 430 is the stronger of the two: yield strength 310 MPa (45 ksi) against 250 MPa (36.3 ksi) for S40975, about 24% more; tensile strength follows at 500 MPa (72.5 ksi) vs 440 MPa (63.8 ksi). 430 is harder — 155 HB against 145 HB for S40975 — which matters for wear surfaces and threads. 430 runs hotter in service (815°C vs 675°C continuous). On the shop floor, S40975 welds better (very good vs good) and S40975 forms better (very good vs good).

430Choose it when strength drives the design, or when surface hardness matters.

S40975Choose it when it will be welded.

430 vs S40975: properties

430S40975

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

500 MPa72.5 ksi
440 MPa63.8 ksi

Yield Strength (0.2% offset)

310 MPa45 ksi
250 MPa36.3 ksi

Shear Strength

350 MPa50.8 ksi
290 MPa42.1 ksi

Fatigue Strength (Endurance Limit)

240 MPa34.8 ksi
230 MPa33.4 ksi

Fracture Toughness (K_IC)

70 MPa·√m63.7 ksi·√in
—

Charpy V-Notch Impact (RT)

25 J18.4 ft·lbf
45 J33.2 ft·lbf

Hardness, Brinell

155 HB
145 HB

Hardness, Rockwell B

82 HRB
78 HRB

Hardness, Vickers

160 HV
152 HV

Compressive Strength

—
250 MPa36.3 ksi

Same in both: Elastic (Young's) Modulus 200 GPa29 Msi · Shear Modulus 77 GPa11.2 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.28 · Elongation at Break 30% · Reduction in Area 65%

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
24.9 W/m·K14.4 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

10.4 µm/m·K5.8 µin/in·°F
11.7 µm/m·K6.5 µin/in·°F

Max Service Temperature (continuous)

815°C1,499 °F
675°C1,247 °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 2.9 % IACS · Electrical Resistivity 6×10⁻⁷ Ω·m23.6 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.25 V
-0.3 V

Corrosion Resistance

55 / 100
42 / 100

Manufacturability

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

Machinability

50 / 100
55 / 100

Machinability Rating (AISI 1212 = 100 %)

54%
65%

Weldability

60 / 100
78 / 100

Formability (cold)

65 / 100
80 / 100

Brazeability / Solderability

60 / 100
65 / 100

Polishability

80 / 100
55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

40 MJ/kg17,197 BTU/lb
42 MJ/kg18,057 BTU/lb

Embodied Carbon (primary production)

3.8 kg CO₂/kg
3.4 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
57 kN·m/kg

Modulus of Resilience

240 kJ/m³
156 kJ/m³

Thermal Diffusivity

7.3 mm²/s
7 mm²/s

Thermal Shock Resistance Index

6
5

Same in both: Specific Stiffness (E / density) 26 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 scale430S40975

Manufacturing and finishing

Capability430S40975
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 S40975 — frequently asked

Is 430 stronger than S40975?

Yes. 430 has a typical yield strength of 310 MPa (45 ksi) against 250 MPa (36.3 ksi) for S40975 — about 24% more. Tensile strength is 500 MPa (72.5 ksi) vs 440 MPa (63.8 ksi).

Which is cheaper, 430 or S40975?

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 is easier to machine, 430 or S40975?

S40975. Its machinability rates good (55/100) against fair (50/100) for 430; for welding the order is S40975 first (very good, 78/100) then 430 (good, 60/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 430 and S40975 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.