Stainless Steel 1.4123 +QT52 (+QT 50–54 HRC)
Heat-treated state
EN 1.4123
Use for shafts, cages, pump and valve components where impact toughness matters more than peak wear resistance.
Values for the +QT52 condition
Other 1.4123 tempers and conditions
1.4123 is listed in 5 conditions; see the grade overview at 1.4123.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Spheroidize annealed | Choose when the softest, most machinable structure is needed for deep drilling, thread rolling or cold forming of bearing-ring blanks. | 540 | 800 | 18 | 21 HRC | — |
+ADefault Annealed | Standard stock condition for machining of blanks before hardening; max hardness limited for turning and drilling. | 600 | 880 | 14 | 25 HRC | — |
+QT52This page +QT 50–54 HRC | Use for shafts, cages, pump and valve components where impact toughness matters more than peak wear resistance. | 1,500 | 1,750 | 7 | 52 HRC | — |
+QT high tempered ~500–525 °C (secondary hardening) 57–59 HRC | Pick for bearings and parts running hot (up to ~350–400 °C) or when dimensional stability after nitriding/coating cycles is required. | 1,800 | 2,100 | 4 | 58 HRC | — |
+QT 58–60 HRC | Standard bearing condition: maximum hardness and rolling-contact fatigue life for corrosion-exposed bearings and valve parts up to ~200 °C. | 1,850 | 2,200 | 3 | 59 HRC | — |
What is 1.4123 +QT52?
1.4123 +QT52 is 1.4123 heat treated to +QT52 — use for shafts, cages, pump and valve components where impact toughness matters more than peak wear resistance. 1.4123 +QT52 has a yield strength of 1,500 MPa (218 ksi) and a tensile strength of 1,750 MPa (254 ksi) — stronger than 100% of stainless steel grades. Elongation at break is 7% and the elastic modulus is 205 GPa (29.7 Msi). 1.4123 +QT52 has a density of 7.68 g/cm³ (0.277 lb/in³), lighter than 94% of stainless steel grades. It melts at 1,400°C (2,552 °F). +A is the default condition FabDigit quotes; +QT52 is available on request or by drawing note.
Advantages
- High strength — 1,500 MPa (218 ksi), better than 100% of stainless steel grades
- Polishes to a fine finish — 85/100, better than 97% of stainless steel grades
Limitations
- Difficult to machine — 12/100, worse than 100% of stainless steel grades
- Limited ductility — 7%, worse than 99% of stainless steel grades
- Difficult to weld — 20/100, worse than 95% of stainless steel grades
- Limited service temperature — 350°C (662 °F), worse than 84% of stainless steel grades
- Needs corrosion protection — 46/100, worse than 82% of stainless steel grades
1.4123 +QT52 properties
Typical room-temperature values for 1.4123 +QT52; 13 are specific to this condition. Other listed values are 1.4123 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
1.4123 +QT52 has a density of 7.68 g/cm³ (0.277 lb/in³), lighter than 94% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical15
1.4123 +QT52 has a yield strength of 1,500 MPa (218 ksi) and a tensile strength of 1,750 MPa (254 ksi) — stronger than 100% of stainless steel grades. Elongation at break is 7% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
1.4123 +QT52 is rated for continuous service to 350°C (662 °F). It conducts heat at 20 W/m·K (11.6 BTU/hr·ft·°F), better than 74% of stainless steel grades. Thermal expansion is 10.5 µm/m·K (5.83 µin/in·°F).
Electrical3
1.4123 +QT52 conducts electricity at 2.5 % IACS, better than 75% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (46/100), worse than 82% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4123 +QT52 takes about 60 MJ of energy and emits 4.8 kg of CO₂ — more than 70% of stainless steel grades. Typical recycled content is 25%.
Manufacturability8
1.4123 +QT52's machinability is not recommended (12/100, worse than 100% of stainless steel grades); weldability poor (20/100); formability poor (30/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1.4123 +QT52
Is 1.4123 easy to machine?
Machine in the annealed/spheroidized condition with rigid setups, sharp coated carbide and generous coolant; after hardening only grinding, honing, EDM or hard turning with CBN is practical.
Can 1.4123 be welded?
Essentially not weldable for structural use — high carbon plus nitrogen gives hard, crack-prone martensite; if repair is unavoidable, preheat 250–300 °C and temper immediately after.
Can 1.4123 be formed, bent or molded?
Hot forge 1100–850 °C with slow cooling and immediate anneal; cold forming is limited to light straightening or thread rolling in the spheroidized state.
What surface finishes work on 1.4123?
Passivate per AMS 2700 or ASTM A967 after grinding; the clean remelted structure polishes to a mirror finish and accepts PVD (TiN, DLC) or plasma nitriding below the tempering temperature.
1.4123 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 |
|---|---|---|
| C | 0.35 – 0.45 | 0.4 |
| Si | ≤ 0.6 | 0.3 |
| Mn | ≤ 0.6 | 0.3 |
| P | ≤ 0.03 | — |
| Slow S for rolling-contact fatigue cleanliness | ≤ 0.01 | — |
| Cr | 15 – 16 | 15.5 |
| Mo | 1.5 – 2 | 1.8 |
| V | 0.2 – 0.4 | 0.3 |
| Npressurized/solution nitrogen, raises PREN and hardness retention | 0.15 – 0.25 | 0.2 |
| Niresidual | ≤ 0.5 | — |
| Fe | balance | — |
1.4123 +QT52 — frequently asked
What is 1.4123 +QT52 used for?
1.4123 +QT52 is typically used for corrosion-resistant rolling bearings, aerospace bearings, precision instrument bearings and valve seats. In short: corrosion-resistant bearing steel; N-alloyed, better than 440C; high hardness retention.
What is the yield strength of 1.4123 +QT52?
1.4123 +QT52 has a typical yield strength of 1,500 MPa (218 ksi) and a tensile strength of 1,750 MPa (254 ksi) — stronger than 100% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is 1.4123 +QT52 easy to machine?
Not especially — machinability is rated not recommended (12/100, worse than 100% of stainless steel grades). Machine in the annealed/spheroidized condition with rigid setups, sharp coated carbide and generous coolant; after hardening only grinding, honing, EDM or hard turning with CBN is practical.
Can 1.4123 +QT52 be welded?
Not readily — weldability is rated poor (20/100). Essentially not weldable for structural use — high carbon plus nitrogen gives hard, crack-prone martensite; if repair is unavoidable, preheat 250–300 °C and temper immediately after.
What surface finishes work on 1.4123 +QT52?
Passivate per AMS 2700 or ASTM A967 after grinding; the clean remelted structure polishes to a mirror finish and accepts PVD (TiN, DLC) or plasma nitriding below the tempering temperature.
Can 1.4123 +QT52 be formed, bent or molded?
Hot forge 1100–850 °C with slow cooling and immediate anneal; cold forming is limited to light straightening or thread rolling in the spheroidized state.
What is the maximum service temperature of 1.4123 +QT52?
1.4123 +QT52 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.
Sources
- EN 10088-3 Stainless steels — Technical delivery conditions for semi-finished products, bars, rods — CEN (2014)
- XD15NW nitrogen-alloyed martensitic stainless bearing steel — Aubert & Duval (2020)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
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.