Nickel Alloy Alloy 689
UNS N07252
Alloy 689 (UNS N07252) is a precipitation-hardenable, low-expansion Ni-Cr superalloy strengthened by gamma-prime, supplied solution-annealed (SA), solution-treated and aged (STA, STA-1010), direct-aged or hot-finished.
Reference datasheet — Alloy 689 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the STA condition
Alloy 689 tempers and conditions
Alloy 689 is supplied in 5 conditions, soft to hard. STA is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Softest supplied condition for machining, forming or welding before the ageing treatment. | 585 | 965 | 32 | 22 HRC | — |
As-hot-worked / as-forged | Intermediate mill product supplied for further forging or re-heat-treatment; properties not guaranteed. | 690 | 1,050 | 24 | 28 HRC | 1.5 % IACS |
Double aged | Stabilising intermediate age before the final age; chosen for long-time creep and rupture ductility at 700–815 °C. | 820 | 1,200 | 18 | 34 HRC | 1.5 % IACS |
STADefault Solution treated and aged | Standard fully heat-treated condition for turbine discs, shafts and bolting up to ~815 °C. | 840 | 1,240 | 16 | 35 HRC | — |
Low-temperature solution (≈1010 °C) + 760 °C age | Finer grain, higher room- and intermediate-temperature strength; use where tensile/LCF strength matters more than creep-rupture life. | 900 | 1,310 | 18 | 37 HRC | 1.4 % IACS |
What is Alloy 689?
Alloy 689 (UNS N07252) is a precipitation-hardenable, low-expansion Ni-Cr superalloy strengthened by gamma-prime, supplied solution-annealed (SA), solution-treated and aged (STA, STA-1010), direct-aged or hot-finished. It is used where high strength must be combined with dimensional stability at temperature, typically as bar, forgings and machined fixtures, giving 840 MPa yield, 1240 MPa tensile, 16 % elongation and 331 HB (35 HRC) with service to 815 °C. The roughly 3.6 % Ti+Al makes it prone to strain-age cracking on reheating, and machinability is poor (score 13), so plan for grinding or EDM after ageing. Alloy 689 has a density of 8.27 g/cm³ (0.299 lb/in³), lighter than 56% of nickel alloy grades. It melts at 1,315°C (2,399 °F). Alloy 689 has a yield strength of 840 MPa (122 ksi) and a tensile strength of 1,240 MPa (180 ksi) — stronger than 89% of nickel alloy grades. Elongation at break is 16% and the elastic modulus is 206 GPa (29.9 Msi).
What is Alloy 689 used for?
- Precision high-temperature fixtures
- Instrumentation components in hot zones
- High-temperature bolting
- Turbine hardware forgings
- Heat-treat and brazing jigs
- Dimensionally critical hot-section brackets
Advantages
- High strength — 840 MPa (122 ksi), better than 89% of nickel alloy grades
Limitations
- High embodied carbon — 15 kg CO₂/kg, worse than 87% of nickel alloy grades
- Limited ductility — 16%, worse than 79% of nickel alloy grades
- Difficult to weld — 30/100, worse than 78% of nickel alloy grades
Alloy 689 properties
Typical room-temperature values for Alloy 689-STA; bars are the position among nickel alloy grades.
Physical3
Alloy 689 has a density of 8.27 g/cm³ (0.299 lb/in³), lighter than 56% of nickel alloy grades. It melts at 1,315°C (2,399 °F).
Mechanical14
Alloy 689 has a yield strength of 840 MPa (122 ksi) and a tensile strength of 1,240 MPa (180 ksi) — stronger than 89% of nickel alloy grades. Elongation at break is 16% and the elastic modulus is 206 GPa (29.9 Msi).
Thermal6
Alloy 689 is rated for continuous service to 815°C (1,499 °F). It conducts heat at 11.7 W/m·K (6.76 BTU/hr·ft·°F), better than 61% of nickel alloy grades. Thermal expansion is 11.9 µm/m·K (6.61 µin/in·°F).
Electrical3
Alloy 689 conducts electricity at 1.5 % IACS, better than 50% of nickel alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (70/100), worse than 77% of nickel alloy grades.
Sustainability4
Producing a kilogram of Alloy 689 takes about 230 MJ of energy and emits 15 kg of CO₂ — more than 91% of nickel alloy grades. Typical recycled content is 30%.
Manufacturability8
Alloy 689's machinability is not recommended (13/100, worse than 82% of nickel alloy grades); weldability poor (30/100); formability fair (35/100).
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 nickel alloy family
Yield strength against density for every nickel alloy grade FabDigit runs. Alloy 689 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Alloy 689
Is Alloy 689 easy to machine?
Machine in the solution-annealed condition where possible; rigid setups, positive-rake carbide or ceramic tools, low speed / heavy feed and flood coolant, and expect grinding or EDM for finishing after ageing.
Can Alloy 689 be welded?
GTAW with matched or Ni-Cr-Co filler on solution-annealed material only, low heat input, followed by full re-solution and age — the ~3.6 % Ti+Al makes it prone to strain-age cracking on reheating.
Can Alloy 689 be formed, bent or molded?
Hot work at roughly 1050–1180 °C with generous reheats; cold forming is limited to mild bends in the annealed state because of very high work-hardening rate.
Alloy 689 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 |
|---|---|---|
| Ccarbide former for grain-boundary strength | 0.1 – 0.2 | 0.15 |
| Cr | 18 – 20 | 19 |
| Co | 9 – 11 | 10 |
| Mosolid-solution strengthener | 9 – 10.5 | 10 |
| Tiγ′ former | 2.25 – 2.75 | 2.6 |
| Alγ′ former | 0.75 – 1.25 | 1 |
| Fe | ≤ 2 | 1 |
| Mn | ≤ 0.5 | |
| Si | ≤ 0.5 | |
| Bgrain-boundary creep resistance | 0 – 0.01 | 0.01 |
| S | ≤ 0.02 | |
| P | ≤ 0.02 | |
| Nibalance, nominally ~56 % | balance |
What surface finishes work on Alloy 689?
Grit blast plus pickle or vacuum-clean before brazing/coating; shot peening is standard for fatigue life, and aluminide or MCrAlY coatings are used for hot-gas surfaces — anodizing does not apply.
Surface treatments FabDigit runs on nickel alloy 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).
Plating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Nickel Alloy Alloy 689 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- N07252
How much does Alloy 689 cost?
Alloy 689 is a high-cost nickel alloy ($$$$), pricier than about 78% 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.
Alloy 689 — frequently asked
What is Alloy 689 used for?
Alloy 689 is typically used for precision high-temperature fixtures, instrumentation components in hot zones, high-temperature bolting, turbine hardware forgings, heat-treat and brazing jigs and dimensionally critical hot-section brackets. In short: dimensional stability at 815 °C; aged strength near 1240 MPa; strain-age cracking sensitive.
What is the yield strength of Alloy 689?
Alloy 689 has a typical yield strength of 840 MPa (122 ksi) and a tensile strength of 1,240 MPa (180 ksi) — stronger than 89% of nickel alloy grades. Strength varies by condition: see the 5 listed tempers.
Is Alloy 689 easy to machine?
Not especially — machinability is rated not recommended (13/100, worse than 82% of nickel alloy grades). Machine in the solution-annealed condition where possible; rigid setups, positive-rake carbide or ceramic tools, low speed / heavy feed and flood coolant, and expect grinding or EDM for finishing after ageing.
Can Alloy 689 be welded?
Not readily — weldability is rated poor (30/100). GTAW with matched or Ni-Cr-Co filler on solution-annealed material only, low heat input, followed by full re-solution and age — the ~3.6 % Ti+Al makes it prone to strain-age cracking on reheating.
What surface finishes work on Alloy 689?
Grit blast plus pickle or vacuum-clean before brazing/coating; shot peening is standard for fatigue life, and aluminide or MCrAlY coatings are used for hot-gas surfaces — anodizing does not apply.
Can Alloy 689 be formed, bent or molded?
Hot work at roughly 1050–1180 °C with generous reheats; cold forming is limited to mild bends in the annealed state because of very high work-hardening rate.
What is the maximum service temperature of Alloy 689?
Alloy 689 is rated for continuous use to about 815°C (1,499 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Alloy 689-STA and Alloy 689-SA?
STA is the default condition — standard fully heat-treated condition for turbine discs, shafts and bolting up to ~815 °C. SA: softest supplied condition for machining, forming or welding before the ageing treatment. Yield strength is 840 MPa in STA versus 585 MPa in SA.
How much does Alloy 689 cost?
Alloy 689 is a high-cost nickel alloy ($$$$), pricier than about 78% 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.
Sources
- ASM Specialty Handbook: Heat-Resistant Materials — ASM International (1997)
- ASM Handbook Vol. 1: Properties and Selection — Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Superalloys II (Sims, Stoloff, Hagel) — Wiley (1987)
- ASTM B637 — Precipitation-Hardening Nickel Alloy Bars, Forgings and Forging Stock for High-Temperature Service — ASTM International (2018)
- UNS N07252 alloy designation record — SAE/ASTM Unified Numbering System (2020)
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.