Stainless Steel CX
also Corrax-like, Corrax
CX (CX, Corrax) is a precipitation-hardening stainless powder for laser powder bed fusion, a 12Cr-9Ni-Al composition that hardens by aging rather than quenching.
Values for the As Printed condition
CX tempers and conditions
CX is supplied in 6 conditions, soft to hard. As Printed is the default FabDigit quotes; the values on this page are for it.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Hot isostatic pressed | Choose for fatigue- or pressure-critical parts where residual LPBF porosity must be closed before aging. | 790 | 1,030 | 16 | 34 HRC | 2.2 % IACS |
~850–900 °C, air/gas cooled to soft martensite | Resets the microstructure and homogenises AM texture before aging; softest, most machinable condition. | 800 | 1,050 | 14 | 34 HRC | 2.2 % IACS |
As PrintedDefault as-built LPBF, soft martensitic condition | Pick for parts that will be machined/EDM'd first and aged afterwards; already ~33 HRC with good machinability. | 900 | 1,100 | 11 | 33 HRC | 2.2 % IACS |
500–560 °C hold (partially ages the alloy) | Use to remove build stresses before plate removal; note the hold overlaps the aging window so hardness and strength rise. | 1,300 | 1,450 | 8 | 45 HRC | 2.3 % IACS |
Aged 560 °C | Pick when impact toughness and crack resistance matter more than peak hardness (large inserts, shock-loaded tooling). | 1,330 | 1,450 | 8 | 45 HRC | 2.4 % IACS |
aged ~525 °C / 4–6 h, ≈50 HRC | Standard service condition for injection-mould inserts: peak hardness and wear resistance with minimal dimensional change. | 1,550 | 1,670 | 5 | 50 HRC | — |
What is CX?
CX (CX, Corrax) is a precipitation-hardening stainless powder for laser powder bed fusion, a 12Cr-9Ni-Al composition that hardens by aging rather than quenching. It is used for conformally cooled mould inserts and tooling: as printed it provides 900 MPa yield, 1100 MPa tensile, 11 % elongation and 33 HRC, with aging to about 50 HRC available, and it can be supplied stress relieved, HIPed, solution annealed or aged at 560 °C. Service is limited to roughly 350 °C, machinability is moderate (score 38), and parts are only produced by LPBF, so build cost and geometry drive the choice. CX has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,400°C (2,552 °F). CX has a yield strength of 900 MPa (131 ksi) and a tensile strength of 1,100 MPa (160 ksi) — stronger than 98% of stainless steel grades. Elongation at break is 11% and the elastic modulus is 185 GPa (26.8 Msi).
What is CX used for?
- Conformally cooled injection mould inserts
- Mould cores and cavities
- Optical-grade moulding surfaces
- Blow and extrusion mould tooling
- Medical device moulding tools
- Tooling for corrosive polymers such as PVC
- Press and die tooling components
Advantages
- High strength — 900 MPa (131 ksi), better than 98% of stainless steel grades
- Polishes to a fine finish — 85/100, better than 97% of stainless steel grades
Limitations
- Limited ductility — 11%, worse than 96% of stainless steel grades
- High embodied carbon — 6.8 kg CO₂/kg, worse than 95% of stainless steel grades
- Limited service temperature — 350°C (662 °F), worse than 84% of stainless steel grades
- Low fracture toughness — 70 MPa·√m (63.7 ksi·√in), worse than 83% of stainless steel grades
- Limited formability — 25/100, worse than 78% of stainless steel grades
CX properties
Typical room-temperature values for CX-As Printed; bars are the position among stainless steel grades.
Physical3
CX has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical16
CX has a yield strength of 900 MPa (131 ksi) and a tensile strength of 1,100 MPa (160 ksi) — stronger than 98% of stainless steel grades. Elongation at break is 11% and the elastic modulus is 185 GPa (26.8 Msi).
Thermal6
CX is rated for continuous service to 350°C (662 °F). It conducts heat at 18 W/m·K (10.4 BTU/hr·ft·°F), better than 73% of stainless steel grades. Thermal expansion is 10.8 µm/m·K (6 µin/in·°F).
Electrical3
CX conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (55/100), worse than 71% of stainless steel grades.
Sustainability4
Producing a kilogram of CX takes about 78 MJ of energy and emits 6.8 kg of CO₂ — more than 87% of stainless steel grades. Typical recycled content is 25%.
Manufacturability8
CX's machinability is fair (38/100, better than 63% of stainless steel grades); weldability very good (70/100); formability poor (25/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the stainless steel family
Yield strength against density for every stainless steel grade FabDigit runs. CX is highlighted; hover a dot for its name, or open the interactive family chart.
Working with CX
Is CX easy to machine?
Machine in the as-printed or solution-annealed state (~33 HRC) with carbide/coated tools and rigid setups; after aging to 50 HRC switch to hard-milling, grinding or EDM.
Can CX be welded?
Weldable without preheat using matching low-carbon maraging stainless filler or TIG autogenous repair; re-age at 525 °C to restore weld-zone hardness.
Can CX be formed, bent or molded?
LPBF only in practice — print with parameter sets for 12Cr-9Ni-Al, keep build plate warm and stress relieve before plate removal; cold forming of finished parts is not viable.
Manufacturability
The process limits FabDigit's quote engine applies to CX. Design inside these and the part quotes instantly; outside them it routes to an engineer.
3D printing
| Technologies | DMLS |
|---|---|
| Layer height | 20 – 60 µmdefault 30 µm |
| Minimum wall / feature | 0.5 / 0.3 mm |
| Build envelope | 250 × 250 × 325 mm |
| Supports | Yes |
| Anisotropy | Mild |
| Mandatory post-processing | heat treatment |
CX chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Clow carbon, maraging type | ≤ 0.03 | 0.02 |
| Si | 0.1 – 0.5 | 0.3 |
| Mn | 0.1 – 0.5 | 0.3 |
| Crpassivity | 11.5 – 12.5 | 12 |
| Nimartensite + Ni-Al precipitates | 8.5 – 9.5 | 9 |
| Mopitting resistance | 1.2 – 1.6 | 1.4 |
| AlNiAl precipitation hardening | 1.4 – 1.8 | 1.6 |
| Ogas-atomized powder | ≤ 0.05 | 0.03 |
| Fe | balance |
What surface finishes work on CX?
Takes a mirror polish for optical mould surfaces; passivate after machining, and PVD or nitriding can be applied below the aging temperature to avoid softening.
Surface treatments FabDigit runs on stainless steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Passivation
Organic Coating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Stainless Steel CX in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Trade names
- Corrax-likeCorrax
How much does CX cost?
CX is a standard-cost stainless steel ($$), cheaper than about 82% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
CX — frequently asked
What is CX used for?
CX is typically used for conformally cooled injection mould inserts, mould cores and cavities, optical-grade moulding surfaces, blow and extrusion mould tooling, medical device moulding tools and tooling for corrosive polymers such as PVC. In short: printed corrosion tool steel.
What is the yield strength of CX?
CX has a typical yield strength of 900 MPa (131 ksi) and a tensile strength of 1,100 MPa (160 ksi) — stronger than 98% of stainless steel grades. Strength varies by condition: see the 6 listed tempers.
Is CX easy to machine?
Not especially — machinability is rated fair (38/100, better than 63% of stainless steel grades). Machine in the as-printed or solution-annealed state (~33 HRC) with carbide/coated tools and rigid setups; after aging to 50 HRC switch to hard-milling, grinding or EDM.
Can CX be welded?
Yes — weldability is rated very good (70/100). Weldable without preheat using matching low-carbon maraging stainless filler or TIG autogenous repair; re-age at 525 °C to restore weld-zone hardness.
What surface finishes work on CX?
Takes a mirror polish for optical mould surfaces; passivate after machining, and PVD or nitriding can be applied below the aging temperature to avoid softening.
Can CX be formed, bent or molded?
LPBF only in practice — print with parameter sets for 12Cr-9Ni-Al, keep build plate warm and stress relieve before plate removal; cold forming of finished parts is not viable.
What is the maximum service temperature of CX?
CX is rated for continuous use to about 350°C (662 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between CX As Printed and CX-HIP?
As Printed is the default condition — pick for parts that will be machined/EDM'd first and aged afterwards; already ~33 HRC with good machinability. HIP: choose for fatigue- or pressure-critical parts where residual LPBF porosity must be closed before aging. Yield strength is 900 MPa in As Printed versus 790 MPa in HIP.
How much does CX cost?
CX is a standard-cost stainless steel ($$), cheaper than about 82% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Can FabDigit make parts in CX?
Yes — CX is available for 3D printing with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- Uddeholm Corrax — precipitation hardening stainless mould steel — Uddeholm / voestalpine (2020)
- EOS StainlessSteel CX material data sheet — EOS GmbH (2021)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASTM F3184 / ASTM F3055-series practice for PBF stainless steels (analogous requirements) — ASTM (2016)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.