Stainless Steel 27-7Mo vs 330
Stainless Steel · grade comparison
Stainless Steel 27-7Mo and 330 are both stainless steel grades. 27-7Mo is the stronger of the two: yield strength 405 MPa (58.7 ksi) against 270 MPa (39.2 ksi) for 330, about 50% more; tensile strength follows at 800 MPa (116 ksi) vs 585 MPa (84.8 ksi). 27-7Mo is the more ductile: elongation 50% versus 43% for 330, and 27-7Mo is harder (200 HB vs 150 HB). 330 runs hotter in service (1,150°C vs 400°C continuous). On the shop floor, 330 machines more easily (32 vs 18 out of 100) and 27-7Mo sits in a lower cost tier (high, $$$$) than 330 (specialty, $$$$$).
27-7MoChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.
330Choose it when the part sees heat, or when the part is machined in volume.
27-7Mo vs 330: 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
Shear Modulus
Bulk Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
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)
Max Service Temperature (continuous)
Latent Heat of Fusion
Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Electrical Resistivity
Same in both: Electrical Conductivity 1.7 % IACS
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.1 V
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
Castability
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: Typical Recycled Content 40%
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 | 27-7Mo | 330 |
|---|---|---|
| CNC machining | — | Yes |
| Sheet metal | — | Yes |
| Default condition | — | Solution Annealed |
| Relative cost | $$$$ High | $$$$$ Specialty |
| Min. machined wall | — | 0.8 mm |
| Best machined surface | — | Ra 1.6 µm |
| AlCrN | — | Yes |
| AlTiN | — | Yes |
| Black Oxide | — | Yes |
| CVD Al2O3 | — | Yes |
| CVD TiCN | — | Yes |
| CVD TiN | — | Yes |
| Cerakote | — | Yes |
| Chrome Plating | — | Yes |
| CrN | — | Yes |
| DLC | — | Yes |
| Electropolishing | — | Yes |
| HVOF Coating | — | Yes |
| MoS2 | — | Yes |
| Multilayer CVD | — | Yes |
| Nickel Plating | — | Yes |
| PTFE Coating | — | Yes |
| Painting | — | Yes |
| Passivation (Stainless Steel) | — | Yes |
They share 7 finishes: Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Pickling, Plasma Spray, Silver Plating.
27-7Mo vs 330 — frequently asked
Is 27-7Mo stronger than 330?
Yes. 27-7Mo has a typical yield strength of 405 MPa (58.7 ksi) against 270 MPa (39.2 ksi) for 330 — about 50% more. Tensile strength is 800 MPa (116 ksi) vs 585 MPa (84.8 ksi).
Which is cheaper, 27-7Mo or 330?
27-7Mo is the lower-cost material: it sits in the high tier ($$$$) while 330 is specialty ($$$$$). 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, 27-7Mo or 330?
330, by a small margin. Both rate poor for machinability — 32/100 against 18/100 for 27-7Mo.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 27-7Mo and 330 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.