Stainless Steel 301 vs XM-21
Stainless Steel · grade comparison
Stainless Steel 301 and XM-21 are both stainless steel grades. 301 is the stronger of the two: yield strength 570 MPa (82.7 ksi) against 400 MPa (58 ksi) for XM-21, about 43% more; tensile strength follows at 900 MPa (131 ksi) vs 690 MPa (100 ksi). In exchange, XM-21 is the more ductile: elongation 48% versus 25% for 301, and 301 is harder (270 HB vs 200 HB). XM-21 runs hotter in service (800°C vs 425°C continuous). On the shop floor, XM-21 welds better (excellent vs good) and XM-21 sits in a lower cost tier (standard, $$) than 301 (premium, $$$).
301Choose it when strength drives the design.
XM-21Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
301 vs XM-21: 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
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Rockwell C
Hardness, Vickers
Same in both: Shear Modulus 77 GPa11.2 Msi
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Liquidus Temperature
Thermal
How each material carries heat and how hot it can run.
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 16.2 W/m·K9.4 BTU/hr·ft·°F · Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°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 Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Brazeability / Solderability
Castability
Same in both: Machinability 35 / 100 · Polishability 80 / 100
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
Thermal Shock Resistance Index
Same in both: Thermal Diffusivity 4.1 mm²/s
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 | 301 | XM-21 |
|---|---|---|
| Sheet metal | Yes | — |
| Default condition | Cold Rolled | — |
| Relative cost | $$$ Premium | $$ Standard |
| Min. machined wall | — | — |
| Best machined surface | — | — |
| Black Oxide | Yes | — |
| Cerakote | Yes | — |
| Chrome Plating | Yes | — |
| Electropolishing | Yes | — |
| Nickel Plating | Yes | — |
| PTFE Coating | Yes | — |
| Painting | Yes | — |
| Passivation (Stainless Steel) | Yes | — |
| Powder Coating | Yes | — |
They share 7 finishes: Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Pickling, Plasma Spray, Silver Plating.
301 vs XM-21 — frequently asked
Is 301 stronger than XM-21?
Yes. 301 has a typical yield strength of 570 MPa (82.7 ksi) against 400 MPa (58 ksi) for XM-21 — about 43% more. Tensile strength is 900 MPa (131 ksi) vs 690 MPa (100 ksi).
Which is cheaper, 301 or XM-21?
XM-21 is the lower-cost material: it sits in the standard tier ($$) while 301 is premium ($$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
Which welds better, 301 or XM-21?
XM-21. Its weldability rates excellent (85/100) against good (65/100) for 301.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 301 and XM-21 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.