Steel 100Cr6 vs 9Cr18Mo
Steel · grade comparison
Steel 100Cr6 and 9Cr18Mo are both steel grades. 9Cr18Mo is the stronger of the two: yield strength 1,900 MPa (276 ksi) against 420 MPa (60.9 ksi) for 100Cr6, about 4.5 times as much; tensile strength follows at 1,970 MPa (286 ksi) vs 660 MPa (95.7 ksi). In exchange, 100Cr6 is the more ductile: elongation 22% versus 2% for 9Cr18Mo, and 9Cr18Mo is harder (680 HV vs 210 HV). 9Cr18Mo runs hotter in service (425°C vs 200°C continuous) and 100Cr6 conducts heat better (45 W/m·K vs 24.2 W/m·K). On the shop floor, 100Cr6 machines more easily (fair vs not recommended) and 100Cr6 sits in a lower cost tier (standard, $$) than 9Cr18Mo (premium, $$$).
100Cr6Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
9Cr18MoChoose it when strength drives the design, or when the part sees heat.
100Cr6 vs 9Cr18Mo: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all 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 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
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
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)
Hardness, Rockwell C
Same in both: Bulk Modulus 160 GPa23.2 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 Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Max Service Temperature (continuous)
Min Service Temperature
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 %)
Formability (cold)
Castability
Brazeability / Solderability
Polishability
Same in both: Weldability 12 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: Typical Recycled Content 30%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
Strength versus weight
Yield strength against density for every steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Manufacturing and finishing
| Capability | 100Cr6 | 9Cr18Mo |
|---|---|---|
| CNC machining | Yes | — |
| Sheet metal | Yes | — |
| Default condition | Annealed | — |
| Relative cost | $$ Standard | $$$ Premium |
| 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 | — |
| E-Coating | Yes | — |
| HVOF Coating | Yes | — |
| Hot-Dip Galvanizing | Yes | — |
| MoS2 | Yes | — |
| Multilayer CVD | Yes | — |
| Nickel Plating | Yes | — |
| PTFE Coating | Yes | — |
| Painting | Yes | — |
They share 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.
100Cr6 vs 9Cr18Mo — frequently asked
Is 9Cr18Mo stronger than 100Cr6?
Yes. 9Cr18Mo has a typical yield strength of 1,900 MPa (276 ksi) against 420 MPa (60.9 ksi) for 100Cr6 — about 4.5 times as much. Tensile strength is 1,970 MPa (286 ksi) vs 660 MPa (95.7 ksi).
Which is cheaper, 100Cr6 or 9Cr18Mo?
100Cr6 is the lower-cost material: it sits in the standard tier ($$) while 9Cr18Mo is premium ($$$). 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, 100Cr6 or 9Cr18Mo?
100Cr6. Its machinability rates fair (45/100) against not recommended (10/100) for 9Cr18Mo.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 100Cr6 and 9Cr18Mo 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.