Stainless Steel 304 vs 347
Stainless Steel · grade comparison
Stainless Steel 304 and 347 are both stainless steel grades. 347 is the stronger of the two: tensile strength 620 MPa (89.9 ksi) against 585 MPa (84.8 ksi) for 304, about 6% more. In exchange, 304 is the more ductile: elongation 55% versus 45% for 347, and 347 is harder (160 HB vs 150 HB). On the shop floor, 304 sits in a lower cost tier (standard, $$) than 347 (premium, $$$).
304Choose it when the part is bent, formed or impact-loaded, or when cost is the deciding factor.
347Choose it when strength drives the design.
304 vs 347: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all stainless steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all stainless steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Bulk Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 193 GPa28 Msi · Shear Modulus 77 GPa11.2 Msi · Poisson's Ratio 0.29 · Fatigue Strength (Endurance Limit) 250 MPa36.3 ksi · Hardness, Rockwell B 82 HRB
Physical
Density and transition temperatures.
Density
Liquidus Temperature
Same in both: Melting Point (Solidus) 1,400°C2,552 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Same in both: Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Max Service Temperature (continuous) 870°C1,598 °F · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Electrical Resistivity
Same in both: Electrical Conductivity 2.4 % IACS
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Galvanic Potential (seawater, vs SCE)
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Brazeability / Solderability
Polishability
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Same in both: Thermal Shock Resistance Index 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.
Manufacturing and finishing
| Capability | 304 | 347 |
|---|---|---|
| Casting & forging | Yes | — |
| Default condition | Annealed | Solution Annealed |
| Relative cost | $$ Standard | $$$ Premium |
| Min. machined wall | 0.8 mm | 0.8 mm |
| Best machined surface | Ra 1.6 µm | Ra 1.6 µm |
Both are offered for CNC machining and Sheet metal. Both take the same 32 finishes: AlCrN, AlTiN, Black Oxide, CVD Al2O3, CVD TiCN, CVD TiN, Cerakote, Chrome Plating, CrN, DLC, Electroless Nickel (EN), Electropolishing and 20 more.
304 vs 347 — frequently asked
Is 347 stronger than 304?
Yes. 347 has a typical tensile strength of 620 MPa (89.9 ksi) against 585 MPa (84.8 ksi) for 304 — about 6% more.
Which is cheaper, 304 or 347?
304 is the lower-cost material: it sits in the standard tier ($$) while 347 is premium ($$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
Which is easier to machine, 304 or 347?
304, by a small margin. Both rate fair for machinability — 45/100 against 38/100 for 347.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 304 and 347 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.