Titanium BT5-1
BT5-1 is an alpha titanium alloy roughly equivalent to Western Ti-5Al-2.5Sn, used annealed as sheet, bar and tube and also available in an ELI variant.
Reference datasheet — BT5-1 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 Annealed condition
BT5-1 tempers and conditions
BT5-1 is supplied in 5 conditions, soft to hard. Annealed 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 |
|---|---|---|---|---|---|---|
extra-low-interstitial (low O, N, H) for cryogenic service | Choose for liquid-hydrogen/liquid-helium hardware where notch toughness at -196 to -253 °C governs. | 720 | 790 | 16 | 29 HRC | 8 W/m·K |
AnnealedDefault mill annealed sheet/plate (700–800 °C, air cool) | Standard stocked condition for sheet and plate; best balance of strength, ductility and weld response. | 800 | 860 | 13 | 300 HB | — |
As-welded deposit | Reference condition for weld-joint design; alpha alloy retains near-parent strength but lower ductility. | 800 | 850 | 8 | 33 HRC | 1.1 % IACS |
Stress relieved | Applied after welding, straightening or heavy machining to remove residual stress without softening. | 820 | 880 | 12 | 33 HRC | 1.1 % IACS |
Hot rolled | Lowest-cost mill condition for parts that will be machined and heat treated afterwards. | 840 | 900 | 11 | 34 HRC | 1.1 % IACS |
Supply forms, finishes and certifications
Ways BT5-1 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
Annealed-Bar | Annealed bar / forging | Supply form |
Annealed-Tube | Annealed tube / pipe | Supply form |
What is BT5-1?
BT5-1 is an alpha titanium alloy roughly equivalent to Western Ti-5Al-2.5Sn, used annealed as sheet, bar and tube and also available in an ELI variant. Annealed material gives about 800 MPa yield, 860 MPa tensile, 13% elongation and 300 HB, with service to 450 °C, good weldability and useful toughness down to cryogenic temperatures. It cannot be strengthened by heat treatment, cold formability is limited and machinability is low (score 22); Ti-5Al-2.5Sn ELI is the direct substitute where Western specifications are required. BT5-1 has a density of 4.46 g/cm³ (0.161 lb/in³), lighter than 78% of titanium grades. It melts at 1,550°C (2,822 °F). BT5-1 has a yield strength of 800 MPa (116 ksi) and a tensile strength of 860 MPa (125 ksi) — stronger than 57% of titanium grades. Elongation at break is 13% and the elastic modulus is 110 GPa (16 Msi).
What is BT5-1 used for?
- cryogenic tanks
- airframe structures
- welded assemblies
Advantages
- High service temperature — 450°C (842 °F), better than 87% of titanium grades
Limitations
- Hard to polish — 60/100, worse than 97% of titanium grades
- Low fracture toughness — 60 MPa·√m (54.6 ksi·√in), worse than 83% of titanium grades
BT5-1 properties
Typical room-temperature values for BT5-1-Annealed; bars are the position among titanium grades.
Physical3
BT5-1 has a density of 4.46 g/cm³ (0.161 lb/in³), lighter than 78% of titanium grades. It melts at 1,550°C (2,822 °F).
Mechanical16
BT5-1 has a yield strength of 800 MPa (116 ksi) and a tensile strength of 860 MPa (125 ksi) — stronger than 57% of titanium grades. Elongation at break is 13% and the elastic modulus is 110 GPa (16 Msi).
Thermal6
BT5-1 is rated for continuous service to 450°C (842 °F). It conducts heat at 7.8 W/m·K (4.51 BTU/hr·ft·°F), worse than 53% of titanium grades. Thermal expansion is 9.4 µm/m·K (5.22 µin/in·°F).
Electrical3
BT5-1 conducts electricity at 1.1 % IACS, worse than 67% of titanium grades.
Chemical & Environmental3
Corrosion resistance is excellent (85/100), worse than 93% of titanium grades.
Sustainability4
Producing a kilogram of BT5-1 takes about 650 MJ of energy and emits 40 kg of CO₂ — less than 75% of titanium grades. Typical recycled content is 25%.
Manufacturability8
BT5-1's machinability is poor (22/100, worse than 55% of titanium grades); weldability very good (75/100); 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 titanium family
Yield strength against density for every titanium grade FabDigit runs. BT5-1 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with BT5-1
Is BT5-1 easy to machine?
Machine like other alpha Ti: rigid setups, sharp uncoated-carbide or coated inserts, low surface speed (25–45 m/min), heavy flood coolant, and never dwell — work hardens and galls readily.
Can BT5-1 be welded?
Good GTAW/plasma/EB weldability with trailing argon or chamber shielding; keep interstitials and moisture out, then stress relieve 540–650 °C; no strengthening heat treatment available.
Can BT5-1 be formed, bent or molded?
Limited cold formability (bend radius ≥4–5t); hot or warm forming at 600–750 °C with subsequent descaling and alpha-case removal is the normal route.
BT5-1 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 stabiliser | 4.3 – 6 | 5 |
| Snneutral solid-solution strengthener | 2 – 3 | 2.5 |
| Zrimpurity limit | ≤ 0.3 | |
| Si | ≤ 0.15 | |
| Fe≤0.25 for кт/ELI grade | ≤ 0.3 | |
| O≤0.10 for кт/ELI grade | ≤ 0.15 | |
| C | ≤ 0.1 | |
| N≤0.03 for кт/ELI | ≤ 0.05 | |
| H≤0.008 for кт/ELI | ≤ 0.02 | |
| Other, eachtotal ≤0.30 | ≤ 0.1 | |
| Ti | balance |
What surface finishes work on BT5-1?
Pickle in HNO₃/HF to strip alpha case and scale; anodic oxide (AMS 2488) or thermal oxidation reduces galling, and shot/glass peening improves fatigue — avoid chloride-bearing marker inks before heat treatment.
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
How much does BT5-1 cost?
BT5-1 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.
BT5-1 — frequently asked
What is BT5-1 used for?
BT5-1 is typically used for cryogenic tanks, airframe structures and welded assemblies. In short: cryogenic-capable alpha titanium; weldable to 450 °C; ti-5Al-2.5Sn equivalent.
What is the yield strength of BT5-1?
BT5-1 has a typical yield strength of 800 MPa (116 ksi) and a tensile strength of 860 MPa (125 ksi) — stronger than 57% of titanium grades. Strength varies by condition: see the 5 listed tempers.
Is BT5-1 easy to machine?
Not especially — machinability is rated poor (22/100, worse than 55% of titanium grades). Machine like other alpha Ti: rigid setups, sharp uncoated-carbide or coated inserts, low surface speed (25–45 m/min), heavy flood coolant, and never dwell — work hardens and galls readily.
Can BT5-1 be welded?
Yes — weldability is rated very good (75/100). Good GTAW/plasma/EB weldability with trailing argon or chamber shielding; keep interstitials and moisture out, then stress relieve 540–650 °C; no strengthening heat treatment available.
What surface finishes work on BT5-1?
Pickle in HNO₃/HF to strip alpha case and scale; anodic oxide (AMS 2488) or thermal oxidation reduces galling, and shot/glass peening improves fatigue — avoid chloride-bearing marker inks before heat treatment.
Can BT5-1 be formed, bent or molded?
Limited cold formability (bend radius ≥4–5t); hot or warm forming at 600–750 °C with subsequent descaling and alpha-case removal is the normal route.
What is the maximum service temperature of BT5-1?
BT5-1 is rated for continuous use to about 450°C (842 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between BT5-1 Annealed and BT5-1-ELI?
Annealed is the default condition — standard stocked condition for sheet and plate; best balance of strength, ductility and weld response. ELI: choose for liquid-hydrogen/liquid-helium hardware where notch toughness at -196 to -253 °C governs. Yield strength is 800 MPa in Annealed versus 720 MPa in ELI.
How much does BT5-1 cost?
BT5-1 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
- GOST 19807 — Titanium and titanium alloys, grades — Gosstandart (1991)
- GOST 22178 — Titanium alloy sheets — Gosstandart (1976)
- ASTM B265 / B348 — Ti and Ti alloy strip, sheet, plate and bar (Grade 6 / Grade 6 ELI) — ASTM International (2020)
- GB/T 3620.1 — Titanium and titanium alloy grades (TA7) — SAC (2016)
- ASM Handbook Vol. 2 — Properties of Nonferrous Alloys (Ti-5Al-2.5Sn) — ASM International (1990)
- Materials Properties Handbook: Titanium Alloys — ASM International (1994)
- MMPDS-style typical design data for Ti-5Al-2.5Sn sheet and bar — Battelle (2022)
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.