Stainless Steel 304 vs XM-15
Stainless Steel · grade comparison
Stainless Steel 304 and XM-15 are both stainless steel grades. Both yield at about 250 MPa — strength does not separate them. XM-15 is harder — 160 HB against 150 HB for 304 — which matters for wear surfaces and threads. XM-15 runs hotter in service (950°C vs 870°C continuous) and 304 conducts heat better (16.2 W/m·K vs 14.5 W/m·K). On the shop floor, 304 forms better (excellent vs very good) and 304 sits in a lower cost tier (standard, $$) than XM-15 (high, $$$$).
304Choose it when cost is the deciding factor.
XM-15Choose it when surface hardness matters, or when the part sees heat.
304 vs XM-15: 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.
Elastic (Young's) Modulus
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: 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
Melting Point (Solidus)
Liquidus Temperature
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).
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)
Polishability
Castability
Same in both: Brazeability / Solderability 65 / 100
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 | XM-15 |
|---|---|---|
| CNC machining | Yes | — |
| Sheet metal | Yes | — |
| Casting & forging | Yes | — |
| Default condition | Annealed | — |
| Relative cost | $$ Standard | $$$$ High |
| Min. machined wall | 0.8 mm | — |
| Best machined surface | Ra 1.6 µm | — |
| AlCrN | Yes | — |
| AlTiN | Yes | — |
| Black Oxide | Yes | — |
| CVD Al2O3 | Yes | — |
| CVD TiCN | Yes | — |
| CVD TiN | Yes | — |
| Cerakote | Yes | — |
| Chrome Plating | Yes | — |
| CrN | Yes | — |
| DLC | Yes | — |
| Electropolishing | Yes | — |
| HVOF Coating | Yes | — |
| MoS2 | Yes | — |
| Multilayer CVD | Yes | — |
| Nickel Plating | Yes | — |
| PTFE Coating | Yes | — |
| Painting | Yes | — |
| Passivation (Stainless Steel) | Yes | — |
They share 7 finishes: Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Pickling, Plasma Spray, Silver Plating.
304 vs XM-15 — frequently asked
What is the difference between 304 and XM-15?
Stainless Steel 304 and XM-15 are both stainless steel grades. Both yield at about 250 MPa — strength does not separate them. XM-15 is harder — 160 HB against 150 HB for 304 — which matters for wear surfaces and threads.
Which is cheaper, 304 or XM-15?
304 is the lower-cost material: it sits in the standard tier ($$) while XM-15 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 XM-15?
304, by a small margin. Both rate fair for machinability — 45/100 against 38/100 for XM-15; for welding the order is 304 first (excellent, 88/100) then XM-15 (very good, 80/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 304 and XM-15 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.