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Stainless Steel 1.4318 vs 304

Stainless Steel · grade comparison

Stainless Steel 1.4318 and 304 are both stainless steel grades. 1.4318 is the stronger of the two: yield strength 380 MPa (55.1 ksi) against 250 MPa (36.3 ksi) for 304, about 52% more; tensile strength follows at 750 MPa (109 ksi) vs 585 MPa (84.8 ksi). 1.4318 is harder — 200 HB against 150 HB for 304 — which matters for wear surfaces and threads. 304 runs hotter in service (870°C vs 400°C continuous).

1.4318Choose it when strength drives the design, or when surface hardness matters.

304Choose it when the part sees heat.

1.4318 vs 304: properties

1.4318304

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

200 GPa29 Msi
193 GPa28 Msi

Shear Modulus

78 GPa11.3 Msi
77 GPa11.2 Msi

Bulk Modulus

150 GPa21.8 Msi
152 GPa22 Msi

Tensile Strength (Ultimate)

750 MPa109 ksi
585 MPa84.8 ksi

Yield Strength (0.2% offset)

380 MPa55.1 ksi
250 MPa36.3 ksi

Elongation at Break

50%
55%

Shear Strength

470 MPa68.2 ksi
415 MPa60.2 ksi

Fatigue Strength (Endurance Limit)

320 MPa46.4 ksi
250 MPa36.3 ksi

Fracture Toughness (K_IC)

200 MPa·√m182 ksi·√in
220 MPa·√m200 ksi·√in

Hardness, Brinell

200 HB
150 HB

Hardness, Rockwell B

88 HRB
82 HRB

Hardness, Vickers

210 HV
160 HV

Compressive Strength

—
250 MPa36.3 ksi

Same in both: Poisson's Ratio 0.29 · Reduction in Area 70% · Charpy V-Notch Impact (RT) 200 J148 ft·lbf

Physical

Density and transition temperatures.

Density

7.9 g/cm³0.29 lb/in³
8 g/cm³0.29 lb/in³

Same in both: Melting Point (Solidus) 1,400°C2,552 °F · Liquidus Temperature 1,450°C2,642 °F

Thermal

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

Thermal Conductivity

15 W/m·K8.7 BTU/hr·ft·°F
16.2 W/m·K9.4 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

16 µm/m·K8.9 µin/in·°F
17.3 µm/m·K9.6 µin/in·°F

Latent Heat of Fusion

270 J/g116 BTU/lb
285 J/g123 BTU/lb

Max Service Temperature (continuous)

400°C752 °F
870°C1,598 °F

Same in both: Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

7.3×10⁻⁷ Ω·m28.7 µΩ·in
7.2×10⁻⁷ Ω·m28.3 µΩ·in

Same in both: Electrical Conductivity 2.4 % IACS

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

55 / 100
70 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.05 V

Manufacturability

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

Machinability

42 / 100
45 / 100

Weldability

85 / 100
88 / 100

Formability (cold)

88 / 100
90 / 100

Brazeability / Solderability

70 / 100
65 / 100

Polishability

75 / 100
88 / 100

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

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)

4.8 kg CO₂/kg
5.4 kg CO₂/kg

Embodied Water

130 L/kg15.6 gal/lb
110 L/kg13.2 gal/lb

Typical Recycled Content

60%
70%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

95 kN·m/kg
73 kN·m/kg

Specific Stiffness (E / density)

25.3 MN·m/kg
24.1 MN·m/kg

Modulus of Resilience

361 kJ/m³
162 kJ/m³

Thermal Diffusivity

3.8 mm²/s
4.1 mm²/s

Thermal Shock Resistance Index

4
3

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 scale3041.4318

Manufacturing and finishing

Capability1.4318304
CNC machining—Yes
Sheet metal—Yes
Casting & forging—Yes
Default condition—Annealed
Relative cost$$ Standard$$ Standard
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.

1.4318 vs 304 — frequently asked

Is 1.4318 stronger than 304?

Yes. 1.4318 has a typical yield strength of 380 MPa (55.1 ksi) against 250 MPa (36.3 ksi) for 304 — about 52% more. Tensile strength is 750 MPa (109 ksi) vs 585 MPa (84.8 ksi).

Which is cheaper, 1.4318 or 304?

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.

When should I choose 1.4318 over 304?

Pick 1.4318 when strength drives the design, or when surface hardness matters. Pick 304 when the part sees heat.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 1.4318 and 304 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.