Steel 80MoCrV42-16 QT-CRYO
Heat-treated state
EN 80MoCrV42-16 · UNS T11350 · AISI/SAE M50 · GB Cr4Mo4V
QT-CRYO = qT + deep cryogenic treatment
Adds a −73 °C (or −196 °C) sub-zero step between tempers to transform retained austenite for precision bearing dimensional stability.
Values for the QT-CRYO condition
Other 80MoCrV42-16 tempers and conditions
80MoCrV42-16 is listed in 7 conditions; see the grade overview at 80MoCrV42-16.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ADefault Solution annealed | Standard stock condition for machining before hardening; soft, ≤255 HB. | 500 | 830 | 16 | 235 HB | — |
Cold drawn, annealed | Small-diameter annealed bar with improved size tolerance and surface for direct machining. | 620 | 880 | 12 | 24 HRC | 2.9 % IACS |
QT 58-60 HRC | Choose when fracture toughness and shock resistance matter more than peak wear life. | 1,900 | 2,200 | 2 | 59 HRC | — |
QT 60-62 HRC | Normal aerospace bearing race/ball condition: austenitize ~1100 °C, quench, triple temper ~540 °C. | 2,050 | 2,400 | 1.5 | 61 HRC | — |
Vacuum induction melted + vacuum arc remelted | Melt-quality designation required for aero-engine mainshaft bearings; supplied annealed, then hardened by the user. | 2,050 | 2,400 | 2 | 62 HRC | 2.7 % IACS |
QT-CRYOThis page QT + deep cryogenic treatment | Adds a −73 °C (or −196 °C) sub-zero step between tempers to transform retained austenite for precision bearing dimensional stability. | 2,100 | 2,450 | 1.5 | 62 HRC | 2.6 % IACS |
QT 62-64 HRC | Maximum wear resistance for tooling and high-load raceways; lowest toughness. | 2,150 | 2,550 | 1 | 63 HRC | — |
What is 80MoCrV42-16 QT-CRYO?
80MoCrV42-16 QT-CRYO is 80MoCrV42-16 heat treated to QT-CRYO — adds a −73 °C (or −196 °C) sub-zero step between tempers to transform retained austenite for precision bearing dimensional stability. 80MoCrV42-16 QT-CRYO has a yield strength of 2,100 MPa (305 ksi) and a tensile strength of 2,450 MPa (355 ksi) — stronger than 100% of steel grades. Elongation at break is 1.5% and the elastic modulus is 205 GPa (29.7 Msi). 80MoCrV42-16 QT-CRYO has a density of 7.97 g/cm³ (0.288 lb/in³), heavier than 94% of steel grades. It melts at 1,420°C (2,588 °F). A is the default condition FabDigit quotes; QT-CRYO is available on request or by drawing note.
Advantages
- High strength — 2,100 MPa (305 ksi), better than 100% of steel grades
- Polishes to a fine finish — 85/100, better than 99% of steel grades
Limitations
- Difficult to machine — 8/100, worse than 100% of steel grades
- Difficult to weld — 3/100, worse than 100% of steel grades
- Limited formability — 2/100, worse than 100% of steel grades
- Limited ductility — 1.5%, worse than 99% of steel grades
- Low electrical conductivity — 2.6 % IACS, worse than 97% of steel grades
80MoCrV42-16 QT-CRYO properties
Typical room-temperature values for 80MoCrV42-16 QT-CRYO; 21 are specific to this condition. Other listed values are 80MoCrV42-16 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
80MoCrV42-16 QT-CRYO has a density of 7.97 g/cm³ (0.288 lb/in³), heavier than 94% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical15
80MoCrV42-16 QT-CRYO has a yield strength of 2,100 MPa (305 ksi) and a tensile strength of 2,450 MPa (355 ksi) — stronger than 100% of steel grades. Elongation at break is 1.5% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
80MoCrV42-16 QT-CRYO is rated for continuous service to 315°C (599 °F). It conducts heat at 22 W/m·K (12.7 BTU/hr·ft·°F), worse than 93% of steel grades. Thermal expansion is 11.3 µm/m·K (6.28 µin/in·°F).
Electrical3
80MoCrV42-16 QT-CRYO conducts electricity at 2.6 % IACS, worse than 97% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (18/100), better than 83% of steel grades.
Sustainability4
Producing a kilogram of 80MoCrV42-16 QT-CRYO takes about 42 MJ of energy and emits 3 kg of CO₂ — more than 92% of steel grades. Typical recycled content is 20%.
Manufacturability7
80MoCrV42-16 QT-CRYO's machinability is not recommended (8/100, worse than 100% of steel grades); weldability not recommended (3/100); formability not recommended (2/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 80MoCrV42-16 QT-CRYO
Is 80MoCrV42-16 easy to machine?
Machine only in the annealed (≤255 HB) condition with rigid setups, coated carbide or cobalt HSS at modest speeds; after hardening to 60+ HRC use CBN grinding or hard turning with CBN and light stock removal.
Can 80MoCrV42-16 be welded?
Essentially non-weldable for structural joints — high carbon and air-hardening response cause cracking; if repair is unavoidable use matching filler, 300–450 °C preheat and immediate re-temper.
Can 80MoCrV42-16 be formed, bent or molded?
Hot forge 1050–1150 °C, stop above 900 °C and slow-cool followed by spheroidize anneal at ~870 °C; no meaningful cold forming.
What surface finishes work on 80MoCrV42-16?
Not anodizable; protect with black oxide, phosphate, thin dense chrome or DLC/silver plating, and keep oil-filmed — bearing raceways are typically finish-ground and honed to Ra <0.05 µm.
80MoCrV42-16 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 | 0.77 – 0.85 | 0.8 |
| Si | ≤ 0.25 | 0.15 |
| Mn | 0.15 – 0.35 | 0.25 |
| PAMS 6491 premium melt | ≤ 0.02 | — |
| SAMS 6491 premium melt | ≤ 0.01 | — |
| Cr | 3.75 – 4.25 | 4 |
| Mo | 4 – 4.5 | 4.25 |
| V | 0.9 – 1.1 | 1 |
| Niresidual | ≤ 0.15 | — |
| Curesidual | ≤ 0.1 | — |
| Wresidual | ≤ 0.25 | — |
| Coresidual | ≤ 0.25 | — |
| Fe | balance | — |
80MoCrV42-16 QT-CRYO — frequently asked
What is 80MoCrV42-16 QT-CRYO used for?
80MoCrV42-16 QT-CRYO is typically used for jet engine main-shaft bearings, turbocharger bearings, high-speed spindle bearings and gas turbine bearings. In short: aerospace high-speed bearing steel; secondary hardening retains hardness; hard-turn or grind after heat treat.
What is the yield strength of 80MoCrV42-16 QT-CRYO?
80MoCrV42-16 QT-CRYO has a typical yield strength of 2,100 MPa (305 ksi) and a tensile strength of 2,450 MPa (355 ksi) — stronger than 100% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is 80MoCrV42-16 QT-CRYO easy to machine?
Not especially — machinability is rated not recommended (8/100, worse than 100% of steel grades). Machine only in the annealed (≤255 HB) condition with rigid setups, coated carbide or cobalt HSS at modest speeds; after hardening to 60+ HRC use CBN grinding or hard turning with CBN and light stock removal.
Can 80MoCrV42-16 QT-CRYO be welded?
Not readily — weldability is rated not recommended (3/100). Essentially non-weldable for structural joints — high carbon and air-hardening response cause cracking; if repair is unavoidable use matching filler, 300–450 °C preheat and immediate re-temper.
What surface finishes work on 80MoCrV42-16 QT-CRYO?
Not anodizable; protect with black oxide, phosphate, thin dense chrome or DLC/silver plating, and keep oil-filmed — bearing raceways are typically finish-ground and honed to Ra <0.05 µm.
Can 80MoCrV42-16 QT-CRYO be formed, bent or molded?
Hot forge 1050–1150 °C, stop above 900 °C and slow-cool followed by spheroidize anneal at ~870 °C; no meaningful cold forming.
What is the maximum service temperature of 80MoCrV42-16 QT-CRYO?
80MoCrV42-16 QT-CRYO is rated for continuous use to about 315°C (599 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 80MoCrV42-16-A and 80MoCrV42-16-QT62?
A is the default condition — standard stock condition for machining before hardening; soft, ≤255 HB. QT62: maximum wear resistance for tooling and high-load raceways; lowest toughness. Yield strength is 500 MPa in A versus 2,150 MPa in QT62.
Sources
- AMS 6491 — Steel Bars, Forgings, Tubing 4.1Cr-4.2Mo-1.0V, Premium Aircraft-Quality (M50) — SAE International (2019)
- EN ISO 683-17 / DIN 17230 rolling bearing steels (80MoCrV42-16, 1.3551) — CEN / DIN (2014)
- GB/T 38885 (Cr4Mo4V / 8Cr4Mo4V) — SAC (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- Lescalloy M50 VIM-VAR bearing steel datasheet — Latrobe/Carpenter Technology (2020)
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.