Stainless Steel 302B vs 304
Stainless Steel · grade comparison
Stainless Steel 302B and 304 are both stainless steel grades. 302B is the stronger of the two: yield strength 275 MPa (39.9 ksi) against 250 MPa (36.3 ksi) for 304, about 10% more; tensile strength follows at 655 MPa (95 ksi) vs 585 MPa (84.8 ksi). 302B is harder — 165 HB against 150 HB for 304 — which matters for wear surfaces and threads. 302B is lighter (7.75 g/cm³ vs 8 g/cm³ for 304) and 302B runs hotter in service (1,090°C vs 870°C continuous). On the shop floor, 304 machines more easily (fair vs poor), 304 welds better (excellent vs good), and 304 forms better (excellent vs very good).
302BChoose it when strength drives the design, or when surface hardness matters.
304Choose it when the part is machined in volume, or when it will be welded.
302B vs 304: 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
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Reduction in Area
Shear Strength
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Compressive Strength
Fracture Toughness (K_IC)
Same in both: Elastic (Young's) Modulus 193 GPa28 Msi · Shear Modulus 77 GPa11.2 Msi · Elongation at Break 55%
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
Max Service Temperature (continuous)
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 Conductivity
Electrical Resistivity
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)
Castability
Brazeability / Solderability
Polishability
Sustainability
Primary-production footprint per kilogram.
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
Same in both: Embodied Energy (primary production) 53 MJ/kg22,786 BTU/lb
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Same in both: 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 | 302B | 304 |
|---|---|---|
| CNC machining | — | Yes |
| Sheet metal | — | Yes |
| Casting & forging | — | Yes |
| Default condition | — | Annealed |
| Relative cost | $$$ Premium | $$ 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.
302B vs 304 — frequently asked
Is 302B stronger than 304?
Yes. 302B has a typical yield strength of 275 MPa (39.9 ksi) against 250 MPa (36.3 ksi) for 304 — about 10% more. Tensile strength is 655 MPa (95 ksi) vs 585 MPa (84.8 ksi).
Which is cheaper, 302B or 304?
304 is the lower-cost material: it sits in the standard tier ($$) while 302B is premium ($$$). 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, 302B or 304?
304. Its machinability rates fair (45/100) against poor (34/100) for 302B; for welding the order is 304 first (excellent, 88/100) then 302B (good, 55/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 302B 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.