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Stainless Steel 2304 vs 312

Stainless Steel · grade comparison

Stainless Steel 2304 and 312 are both stainless steel grades. 312 is the stronger of the two: yield strength 530 MPa (76.9 ksi) against 460 MPa (66.7 ksi) for 2304, about 15% more; tensile strength follows at 760 MPa (110 ksi) vs 680 MPa (98.6 ksi). 312 is harder — 24 HRC against 22 HRC for 2304 — which matters for wear surfaces and threads. On the shop floor, 2304 forms better (good vs fair).

312Choose it when strength drives the design, or when surface hardness matters.

2304 vs 312: properties

2304312

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Bulk Modulus

150 GPa21.8 Msi
160 GPa23.2 Msi

Tensile Strength (Ultimate)

680 MPa98.6 ksi
760 MPa110 ksi

Yield Strength (0.2% offset)

460 MPa66.7 ksi
530 MPa76.9 ksi

Compressive Strength

470 MPa68.2 ksi
540 MPa78.3 ksi

Shear Strength

420 MPa60.9 ksi
460 MPa66.7 ksi

Fatigue Strength (Endurance Limit)

400 MPa58 ksi
350 MPa50.8 ksi

Charpy V-Notch Impact (RT)

220 J162 ft·lbf
120 J88.5 ft·lbf

Hardness, Brinell

240 HB
250 HB

Hardness, Rockwell B

99 HRB
100 HRB

Hardness, Rockwell C

22 HRC
24 HRC

Hardness, Vickers

250 HV
260 HV

Same in both: Elastic (Young's) Modulus 200 GPa29 Msi · Shear Modulus 77 GPa11.2 Msi · Poisson's Ratio 0.3 · Elongation at Break 30% · Reduction in Area 55% · Fracture Toughness (K_IC) 120 MPa·√m109 ksi·√in

Physical

Density and transition temperatures.

Density

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

Same in both: Melting Point (Solidus) 1,385°C2,525 °F · Liquidus Temperature 1,445°C2,633 °F

Thermal

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

Thermal Conductivity

16 W/m·K9.2 BTU/hr·ft·°F
15 W/m·K8.7 BTU/hr·ft·°F

Latent Heat of Fusion

275 J/g118 BTU/lb
270 J/g116 BTU/lb

Max Service Temperature (continuous)

300°C572 °F
280°C536 °F

Same in both: Specific Heat Capacity 480 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 13 µm/m·K7.2 µin/in·°F · Min Service Temperature -50°C-58 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 2.2 % IACS · Electrical Resistivity 8×10⁻⁷ Ω·m31.5 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

74 / 100
72 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.15 V

Manufacturability

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

Machinability Rating (AISI 1212 = 100 %)

40%
25%

Weldability

72 / 100
70 / 100

Formability (cold)

55 / 100
45 / 100

Castability

45 / 100
—

Same in both: Machinability 35 / 100 · Brazeability / Solderability 40 / 100 · Polishability 70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

46 MJ/kg19,776 BTU/lb
55 MJ/kg23,646 BTU/lb

Embodied Carbon (primary production)

3.8 kg CO₂/kg
4.6 kg CO₂/kg

Embodied Water

100 L/kg12 gal/lb
130 L/kg15.6 gal/lb

Typical Recycled Content

70%
60%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

88 kN·m/kg
97 kN·m/kg

Specific Stiffness (E / density)

25.8 MN·m/kg
25.6 MN·m/kg

Modulus of Resilience

529 kJ/m³
702 kJ/m³

Thermal Diffusivity

4.3 mm²/s
4 mm²/s

Same in both: Thermal Shock Resistance Index 4

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 scale3122304

Manufacturing and finishing

Capability2304312
CNC machiningYes—
Sheet metalYes—
Default conditionSolution Annealed—
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.

2304 vs 312 — frequently asked

Is 312 stronger than 2304?

Yes. 312 has a typical yield strength of 530 MPa (76.9 ksi) against 460 MPa (66.7 ksi) for 2304 — about 15% more. Tensile strength is 760 MPa (110 ksi) vs 680 MPa (98.6 ksi).

Which is cheaper, 2304 or 312?

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 2304 over 312?

Pick 312 when strength drives the design, or when surface hardness matters.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 2304 and 312 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.