Stainless Steel 304 vs 348
Stainless Steel · grade comparison
Stainless Steel 304 and 348 are both stainless steel grades. 348 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 348, and 348 is harder (160 HB vs 150 HB). On the shop floor, 304 sits in a lower cost tier (standard, $$) than 348 (high, $$$$).
304Choose it when the part is bent, formed or impact-loaded, or when cost is the deciding factor.
348Choose it when strength drives the design.
304 vs 348: 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)
Elongation at Break
Reduction in Area
Shear Strength
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 193 GPa28 Msi · Shear Modulus 77 GPa11.2 Msi · Poisson's Ratio 0.29 · Yield Strength (0.2% offset) 250 MPa36.3 ksi · Compressive Strength 250 MPa36.3 ksi · Fatigue Strength (Endurance Limit) 250 MPa36.3 ksi · Fracture Toughness (K_IC) 220 MPa·√m200 ksi·√in
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)
Same in both: Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Latent Heat of Fusion 285 J/g123 BTU/lb · 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).
Corrosion Resistance
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
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Polishability
Castability
Same in both: Brazeability / Solderability 65 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Water
Typical Recycled Content
Same in both: Embodied Energy (primary production) 53 MJ/kg22,786 BTU/lb · Embodied Carbon (primary production) 5.4 kg CO₂/kg
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Same in both: Modulus of Resilience 162 kJ/m³ · Thermal Diffusivity 4.1 mm²/s · 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 | 348 |
|---|---|---|
| CNC machining | Yes | — |
| Sheet metal | Yes | — |
| Casting & forging | Yes | — |
| Default condition | Annealed | — |
| Relative cost | $$ Standard | $$$$ High |
| Min. machined wall | 0.8 mm | — |
| Best machined surface | Ra 1.6 µm | — |
| AlCrN | Yes | — |
| AlTiN | Yes | — |
| Black Oxide | Yes | — |
| CVD Al2O3 | Yes | — |
| CVD TiCN | Yes | — |
| CVD TiN | Yes | — |
| Cerakote | Yes | — |
| Chrome Plating | Yes | — |
| CrN | Yes | — |
| DLC | Yes | — |
| Electropolishing | Yes | — |
| HVOF Coating | Yes | — |
| MoS2 | Yes | — |
| Multilayer CVD | Yes | — |
| Nickel Plating | Yes | — |
| PTFE Coating | Yes | — |
| Painting | Yes | — |
| Passivation (Stainless Steel) | Yes | — |
They share 7 finishes: Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Pickling, Plasma Spray, Silver Plating.
304 vs 348 — frequently asked
Is 348 stronger than 304?
Yes. 348 has a typical tensile strength of 620 MPa (89.9 ksi) against 585 MPa (84.8 ksi) for 304 — about 6% more.
Which is cheaper, 304 or 348?
304 is the lower-cost material: it sits in the standard tier ($$) while 348 is high ($$$$). 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 348?
304, by a small margin. Both rate fair for machinability — 45/100 against 38/100 for 348.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 304 and 348 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.