Stainless Steel CX · heat-treated state
Stainless Steel CX Hardened & Tempered
Properties of the Hardened & Tempered condition, compared with the other CX tempers.
Standard service condition for injection-mould inserts: peak hardness and wear resistance with minimal dimensional change.
What is CX Hardened & Tempered?
CX Hardened & Tempered is CX heat treated to Hardened & Tempered — standard service condition for injection-mould inserts: peak hardness and wear resistance with minimal dimensional change. CX Hardened & Tempered has a yield strength of 1,550 MPa (225 ksi) and a tensile strength of 1,670 MPa (242 ksi) — stronger than 100% of stainless steel grades. Elongation at break is 5% and the elastic modulus is 200 GPa (29 Msi). CX Hardened & Tempered 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). As Printed is the default condition FabDigit quotes; Hardened & Tempered is available on request or by drawing note.
Advantages
- High strength — 1,550 MPa (225 ksi), better than 100% of stainless steel grades
- Polishes to a fine finish — 90/100, better than 100% of stainless steel grades
Limitations
- Limited ductility — 5%, worse than 100% of stainless steel grades
- Difficult to machine — 22/100, worse than 95% of stainless steel grades
- High embodied carbon — 6.8 kg CO₂/kg, worse than 95% of stainless steel grades
- Low fracture toughness — 55 MPa·√m (50.1 ksi·√in), worse than 94% of stainless steel grades
- Limited formability — 25/100, worse than 79% of stainless steel grades
CX Hardened & Tempered properties
Typical room-temperature values for CX Hardened & Tempered — 17 properties are specific to this condition; the rest are grade-level values shared by every CX temper. Each bar shows where the value sits among the stainless steel grades in FabDigit's library — further right is higher.
Physical3
CX Hardened & Tempered 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).
Mechanical15
CX Hardened & Tempered has a yield strength of 1,550 MPa (225 ksi) and a tensile strength of 1,670 MPa (242 ksi) — stronger than 100% of stainless steel grades. Elongation at break is 5% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
CX Hardened & Tempered is rated for continuous service to 400°C (752 °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 Hardened & Tempered conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (58/100), worse than 63% of stainless steel grades.
Sustainability4
Producing a kilogram of CX Hardened & Tempered 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 Hardened & Tempered's machinability is poor (22/100, worse than 95% of stainless steel grades); weldability very good (70/100); formability poor (25/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other CX tempers and conditions
CX is also supplied in 5 other conditions. The full side-by-side table is on the CX overview.
- As PrintedDefaultPick for parts that will be machined/EDM'd first and aged afterwards; already ~33 HRC with good machinability.900 MPa yield · 33 HRC
- Hardened & TemperedStandard service condition for injection-mould inserts: peak hardness and wear resistance with minimal dimensional change.1,550 MPa yield · 50 HRC
- Aged 560Pick when impact toughness and crack resistance matter more than peak hardness (large inserts, shock-loaded tooling).1,330 MPa yield · 45 HRC
- Stress RelievedUse to remove build stresses before plate removal; note the hold overlaps the aging window so hardness and strength rise.1,300 MPa yield · 45 HRC
- Solution AnnealedResets the microstructure and homogenises AM texture before aging; softest, most machinable condition.800 MPa yield · 34 HRC
Working with CX Hardened & Tempered
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.
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.
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 | — |
CX Hardened & Tempered — frequently asked
What is CX Hardened & Tempered used for?
CX Hardened & Tempered 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 Hardened & Tempered?
CX Hardened & Tempered has a typical yield strength of 1,550 MPa (225 ksi) and a tensile strength of 1,670 MPa (242 ksi) — stronger than 100% of stainless steel grades. Strength varies by condition: see the 6 listed tempers.
Is CX Hardened & Tempered easy to machine?
Not especially — machinability is rated poor (22/100, worse than 95% 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 Hardened & Tempered 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 Hardened & Tempered?
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 Hardened & Tempered 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 Hardened & Tempered?
CX Hardened & Tempered is rated for continuous use to about 400°C (752 °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.
Can FabDigit make parts in CX Hardened & Tempered?
Yes — CX Hardened & Tempered 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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.