Stainless Steel 1.4008 QT-HH
Hardness band
EN 1.4008
QT-HH = q&T high hardness
Pick for seating faces, wear rings and trim needing hardness and cavitation resistance; toughness and corrosion resistance are reduced and it is not sour-service compliant.
Values for the QT-HH condition
Other 1.4008 tempers and conditions
1.4008 is listed in 5 conditions; see the grade overview at 1.4008.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Choose for maximum machinability of rough castings before final hardening and tempering. | 380 | 590 | 22 | 180 HB | — |
+QT1Default Quenched (≈ 950–1050 °C) and high-tempered (≈ 650–700 °C), Rp0.2 ≥ 440… | Standard delivery condition for pump casings, valve bodies and hydro parts — best balance of strength, toughness and corrosion resistance. | 500 | 690 | 18 | 18 HRC | — |
Quenched and tempered to Rp0.2 ≥ 550 MPa | Higher-strength condition for pressure-retaining valve bodies and stems where extra yield strength is specified. | 600 | 800 | 16 | 24 HRC | — |
As fabricated | Shipping/intermediate condition only — hard, brittle untempered martensite; must be austenitized and tempered before service. | 700 | 900 | 4 | 36 HRC | 2.8 % IACS |
QT-HHThis page Q&T high hardness | Pick for seating faces, wear rings and trim needing hardness and cavitation resistance; toughness and corrosion resistance are reduced and it is not sour-service compliant. | 950 | 1,150 | 8 | 40 HRC | — |
What is 1.4008 QT-HH?
1.4008 QT-HH is 1.4008 heat treated to QT-HH — pick for seating faces, wear rings and trim needing hardness and cavitation resistance; toughness and corrosion resistance are reduced and it is not sour-service compliant. 1.4008 QT-HH has a yield strength of 950 MPa (138 ksi) and a tensile strength of 1,150 MPa (167 ksi) — stronger than 98% of stainless steel grades. Elongation at break is 8% and the elastic modulus is 200 GPa (29 Msi). 1.4008 QT-HH 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). +QT1 is the default condition FabDigit quotes; QT-HH is available on request or by drawing note.
Advantages
- High strength — 950 MPa (138 ksi), better than 98% of stainless steel grades
- Conducts heat well — 25 W/m·K (14.4 BTU/hr·ft·°F), better than 93% of stainless steel grades
- Polishes to a fine finish — 80/100, better than 89% of stainless steel grades
- High electrical conductivity — 2.9 % IACS, better than 87% of stainless steel grades
- Low embodied carbon — 3.6 kg CO₂/kg, better than 83% of stainless steel grades
Limitations
- Limited ductility — 8%, worse than 99% of stainless steel grades
- Low fracture toughness — 45 MPa·√m (41 ksi·√in), worse than 95% of stainless steel grades
- Difficult to machine — 22/100, worse than 95% of stainless steel grades
- Limited formability — 10/100, worse than 95% of stainless steel grades
- Needs corrosion protection — 40/100, worse than 93% of stainless steel grades
1.4008 QT-HH properties
Typical room-temperature values for 1.4008 QT-HH; 16 are specific to this condition. Other listed values are 1.4008 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
1.4008 QT-HH 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
1.4008 QT-HH has a yield strength of 950 MPa (138 ksi) and a tensile strength of 1,150 MPa (167 ksi) — stronger than 98% of stainless steel grades. Elongation at break is 8% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
1.4008 QT-HH is rated for continuous service to 350°C (662 °F). It conducts heat at 25 W/m·K (14.4 BTU/hr·ft·°F), better than 93% of stainless steel grades. Thermal expansion is 10.5 µm/m·K (5.83 µin/in·°F).
Electrical3
1.4008 QT-HH conducts electricity at 2.9 % IACS, better than 87% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (40/100), worse than 93% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4008 QT-HH takes about 53 MJ of energy and emits 3.6 kg of CO₂ — less than 67% of stainless steel grades. Typical recycled content is 70%.
Manufacturability8
1.4008 QT-HH's machinability is poor (22/100, worse than 95% of stainless steel grades); weldability poor (25/100); formability not recommended (10/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1.4008 QT-HH
Is 1.4008 easy to machine?
Machine in the annealed or high-tempered condition with rigid setups, sharp coated carbide, moderate speed (~80–120 m/min) and generous feed to avoid work-hardened glazing; rough-machine before final temper.
Can 1.4008 be welded?
Weldable with matched 410NiMo/E410NiMo or austenitic 309/316L consumables — preheat 200–300 °C, maintain interpass, and post-weld temper at 600–650 °C to restore toughness and avoid hydrogen cracking.
Can 1.4008 be formed, bent or molded?
Sand or investment cast; use adequate risering and controlled slow cooling from the mould to prevent quench cracking, then austenitize 950–1050 °C, air/oil quench and temper.
What surface finishes work on 1.4008?
Passivate per ASTM A967 or electropolish after machining; takes a good mechanical polish and accepts hard chrome, nitriding or HVOF overlays on wear faces — no anodizing.
1.4008 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 |
|---|---|---|
| CASTM CA15M allows up to 0.15 % | 0.05 – 0.1 | 0.07 |
| Si | ≤ 0.8 | 0.5 |
| MnASTM CA15M allows 1.00 % max | ≤ 0.8 | 0.6 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.03 | 0.01 |
| CrCA15M: 11.5–14.0 | 12 – 13.5 | 12.7 |
| NiCA15M limits Ni to 1.0 max — grades are similar but not identical | 1 – 2 | 1.5 |
| MoCA15M: 0.15–1.00 | 0.2 – 0.5 | 0.35 |
| Fe | balance | — |
1.4008 QT-HH — frequently asked
What is 1.4008 QT-HH used for?
1.4008 QT-HH is typically used for pump casings, valve bodies and general corrosion-resistant castings. In short: mo-bearing CA15M equivalent; moderate corrosion and heat resistance; needs preheat and PWHT.
What is the yield strength of 1.4008 QT-HH?
1.4008 QT-HH has a typical yield strength of 950 MPa (138 ksi) and a tensile strength of 1,150 MPa (167 ksi) — stronger than 98% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is 1.4008 QT-HH easy to machine?
Not especially — machinability is rated poor (22/100, worse than 95% of stainless steel grades). Machine in the annealed or high-tempered condition with rigid setups, sharp coated carbide, moderate speed (~80–120 m/min) and generous feed to avoid work-hardened glazing; rough-machine before final temper.
Can 1.4008 QT-HH be welded?
Not readily — weldability is rated poor (25/100). Weldable with matched 410NiMo/E410NiMo or austenitic 309/316L consumables — preheat 200–300 °C, maintain interpass, and post-weld temper at 600–650 °C to restore toughness and avoid hydrogen cracking.
What surface finishes work on 1.4008 QT-HH?
Passivate per ASTM A967 or electropolish after machining; takes a good mechanical polish and accepts hard chrome, nitriding or HVOF overlays on wear faces — no anodizing.
Can 1.4008 QT-HH be formed, bent or molded?
Sand or investment cast; use adequate risering and controlled slow cooling from the mould to prevent quench cracking, then austenitize 950–1050 °C, air/oil quench and temper.
What is the maximum service temperature of 1.4008 QT-HH?
1.4008 QT-HH 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 1.4008 +QT1 and 1.4008 QT-HH?
+QT1 is the default condition — standard delivery condition for pump casings, valve bodies and hydro parts — best balance of strength, toughness and corrosion resistance. QT-HH: pick for seating faces, wear rings and trim needing hardness and cavitation resistance; toughness and corrosion resistance are reduced and it is not sour-service compliant. Yield strength is 500 MPa in +QT1 versus 950 MPa in QT-HH.
Sources
- EN 10283 — Corrosion resistant steel castings (GX7CrNiMo12-1 / 1.4008) — CEN (2010)
- EN 10213 — Steel castings for pressure purposes — CEN (2016)
- ASTM A743/A743M — Castings, Iron-Chromium, Iron-Chromium-Nickel (Gr. CA15M, UNS J91151) — ASTM (2021)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels and High-Performance Alloys (cast martensitic stainless) — ASM International (1990)
- ASM Specialty Handbook: Stainless Steels — ASM International (1994)
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.