Titanium Ti-17
UNS R58650 · GB TC17
Ti-17 (UNS R58650, TC17) is a deep-hardening, beta-rich alpha-beta titanium alloy developed for large jet-engine fan and compressor disks.
Reference datasheet — Ti-17 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
Ti-17 tempers and conditions
Ti-17 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 | Supplied for further hot working, machining of near-net shapes or straightening before the customer performs the ageing cycle. | 880 | 950 | 15 | 31 HRC | 1 % IACS |
As-forged / mill-annealed billet and bar | Raw billet, bar and forging stock condition sold for onward forging; not a design-strength condition. | 930 | 1,020 | 12 | 33 HRC | 1 % IACS |
Overaged | Used where dimensional/thermal stability and toughness matter more than peak strength, e.g. large stabilised disk forgings. | 950 | 1,030 | 12 | 34 HRC | 1 % IACS |
Beta solution treated (above beta transus ~890-900 °C) and aged | Choose when maximum fracture toughness and crack-growth resistance in very thick sections outweigh a modest loss of ductility and fatigue strength. | 1,020 | 1,100 | 7 | 36 HRC | 1 % IACS |
STADefault Solution treated and aged | Standard high-strength condition for fan/compressor disks and thick forgings needing strength plus good LCF life. | 1,075 | 1,150 | 10 | 37 HRC | — |
What is Ti-17?
Ti-17 (UNS R58650, TC17) is a deep-hardening, beta-rich alpha-beta titanium alloy developed for large jet-engine fan and compressor disks. It combines high strength with fracture toughness in thick sections, giving 1075 MPa yield, 1150 MPa tensile, 10% elongation and 37 HRC in STA, with service to 350 °C; it is supplied as billet, forgings and rings in STA, BSTA, ST, OA and as-forged conditions. Machinability is low (score 16), cold forming is impractical and welding is normally excluded from critical rotating hardware. Ti-6Al-2Sn-4Zr-6Mo is the closest alternative where higher temperature capability is needed. Ti-17 has a density of 4.65 g/cm³ (0.168 lb/in³), heavier than 90% of titanium grades. It melts at 1,600°C (2,912 °F). Ti-17 has a yield strength of 1,075 MPa (156 ksi) and a tensile strength of 1,150 MPa (167 ksi) — stronger than 98% of titanium grades. Elongation at break is 10% and the elastic modulus is 112 GPa (16.2 Msi).
What is Ti-17 used for?
- jet engine fan disks
- compressor disks
- high-strength rotating parts
Advantages
- High strength — 1,075 MPa (156 ksi), better than 98% of titanium grades
Limitations
- Difficult to weld — 30/100, worse than 98% of titanium grades
- Limited ductility — 10%, worse than 93% of titanium grades
- Limited formability — 15/100, worse than 93% of titanium grades
- Low fracture toughness — 55 MPa·√m (50.1 ksi·√in), worse than 90% of titanium grades
Ti-17 properties
Typical room-temperature values for Ti-17-STA; bars are the position among titanium grades.
Physical3
Ti-17 has a density of 4.65 g/cm³ (0.168 lb/in³), heavier than 90% of titanium grades. It melts at 1,600°C (2,912 °F).
Mechanical15
Ti-17 has a yield strength of 1,075 MPa (156 ksi) and a tensile strength of 1,150 MPa (167 ksi) — stronger than 98% of titanium grades. Elongation at break is 10% and the elastic modulus is 112 GPa (16.2 Msi).
Thermal6
Ti-17 is rated for continuous service to 350°C (662 °F). It conducts heat at 7 W/m·K (4.04 BTU/hr·ft·°F), worse than 76% of titanium grades. Thermal expansion is 9.4 µm/m·K (5.22 µin/in·°F).
Electrical2
Ti-17 has an electrical resistivity of 1.7×10⁻⁶ Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (85/100), worse than 93% of titanium grades.
Sustainability4
Producing a kilogram of Ti-17 takes about 680 MJ of energy and emits 42 kg of CO₂ — more than 51% of titanium grades. Typical recycled content is 20%.
Manufacturability7
Ti-17's machinability is poor (16/100, worse than 93% of titanium grades); weldability poor (30/100); formability poor (15/100).
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 titanium family
Yield strength against density for every titanium grade FabDigit runs. Ti-17 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Ti-17
Is Ti-17 easy to machine?
Machine like a hard beta-rich titanium: rigid setup, sharp uncoated-carbide or coated inserts, ~15-30 m/min in the aged condition, heavy flood coolant, positive rake and no dwelling to avoid work hardening and edge notching.
Can Ti-17 be welded?
GTAW/EBW is metallurgically possible with full inert or vacuum shielding, but the aged HAZ loses ductility, so post-weld solution+age is required and welding is normally excluded from critical rotating hardware.
Can Ti-17 be formed, bent or molded?
Essentially a hot-work alloy — forge/ring-roll just below or above the beta transus (~850-925 °C) with controlled cooling; cold forming is impractical, so bends and rings are made hot or by machining.
Ti-17 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 |
|---|---|---|
| Alalpha stabilizer | 4.5 – 5.5 | 5 |
| Sn | 1.6 – 2.4 | 2 |
| Zr | 1.6 – 2.4 | 2 |
| Mobeta stabilizer, deep hardenability | 3.5 – 4.5 | 4 |
| Crbeta stabilizer | 3.5 – 4.5 | 4 |
| Fe | ≤ 0.3 | |
| Ocontrolled range | 0.08 – 0.13 | 0.11 |
| C | ≤ 0.05 | |
| N | ≤ 0.05 | |
| H | ≤ 0.01 | |
| Simax (some specs) | ≤ 0.15 | |
| Ti | balance |
What surface finishes work on Ti-17?
Shot peen or low-stress grind highly loaded surfaces; anodic/AMS 2488 conversion coatings, ion plating or dry-film lube prevent galling, and pickling must avoid hydrogen pickup.
Surface treatments FabDigit runs on titanium 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).
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Titanium Ti-17 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- R58650
- GB (China)
- TC17
- Other
- 4970
How much does Ti-17 cost?
Ti-17 is a high-cost titanium ($$$$), 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.
Ti-17 — frequently asked
What is Ti-17 used for?
Ti-17 is typically used for jet engine fan disks, compressor disks and high-strength rotating parts. In short: deep-hardening disk alloy; high fracture toughness; hot-work only, no cold forming.
What is the yield strength of Ti-17?
Ti-17 has a typical yield strength of 1,075 MPa (156 ksi) and a tensile strength of 1,150 MPa (167 ksi) — stronger than 98% of titanium grades. Strength varies by condition: see the 5 listed tempers.
Is Ti-17 easy to machine?
Not especially — machinability is rated poor (16/100, worse than 93% of titanium grades). Machine like a hard beta-rich titanium: rigid setup, sharp uncoated-carbide or coated inserts, ~15-30 m/min in the aged condition, heavy flood coolant, positive rake and no dwelling to avoid work hardening and edge notching.
Can Ti-17 be welded?
Not readily — weldability is rated poor (30/100). GTAW/EBW is metallurgically possible with full inert or vacuum shielding, but the aged HAZ loses ductility, so post-weld solution+age is required and welding is normally excluded from critical rotating hardware.
What surface finishes work on Ti-17?
Shot peen or low-stress grind highly loaded surfaces; anodic/AMS 2488 conversion coatings, ion plating or dry-film lube prevent galling, and pickling must avoid hydrogen pickup.
Can Ti-17 be formed, bent or molded?
Essentially a hot-work alloy — forge/ring-roll just below or above the beta transus (~850-925 °C) with controlled cooling; cold forming is impractical, so bends and rings are made hot or by machining.
What is the maximum service temperature of Ti-17?
Ti-17 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 Ti-17-STA and Ti-17-ST?
STA is the default condition — standard high-strength condition for fan/compressor disks and thick forgings needing strength plus good LCF life. ST: supplied for further hot working, machining of near-net shapes or straightening before the customer performs the ageing cycle. Yield strength is 1,075 MPa in STA versus 880 MPa in ST.
How much does Ti-17 cost?
Ti-17 is a high-cost titanium ($$$$), 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
- AMS 4995 — Titanium Alloy Forgings Ti-5Al-2Sn-2Zr-4Mo-4Cr, Solution and Precipitation Heat Treated — SAE International (2019)
- AMS 4970 — Titanium Alloy Bars, Forgings and Rings Ti-5Al-2Sn-2Zr-4Mo-4Cr — SAE International (2018)
- Materials Properties Handbook: Titanium Alloys — ASM International (1994)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- GB/T 2965 / TC17 (2007)
- Ti-17 (TC17) forging billet datasheets (2023)
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.