MIL-T-9047 - Ti-5Al-2.5Sn Titanium Bars, Billets & Forgings
What Is MIL-T-9047?
MIL-T-9047 is a U.S. Department of Defense military specification for titanium and titanium alloy bars, billets, and forgings (including reforging stock), first issued in 1955.
It does not cover sheet, strip, or plate – those product forms are addressed by the companion specification MIL-T-9046.
Like its companion, MIL-T-9047 consolidates requirements for approximately 20 titanium alloy types in a single document – including commercially pure grades, alpha alloys such as Ti-5Al-2.5Sn, and alpha-beta alloys such as Ti-6Al-4V – which creates procurement challenges because a drawing callout of “MIL-T-9047” alone does not identify the specific alloy required.
Its SAE counterpart, AMS-T-9047, addressed the same product forms under SAE governance. As alloy-specific AMS specifications were published – including AMS 4924 and AMS 4926 for Ti-5Al-2.5Sn bars – both MIL-T-9047 and AMS-T-9047 were scheduled for cancellation beginning in 1999.
The specification remains relevant for legacy programs where drawings have not been updated to current AMS equivalents.
To source material against a MIL-T-9047 callout, you must also provide the alloy composition, condition, and revision letter.
Contact us with those details and we will source the correct material.
Available Forms and Typical Stocked Sizes
Ti-5Al-2.5Sn per MIL-T-9047 round bar in diameters from 0.250″ to approximately 20.000″ and larger, in the annealed condition.
Supplied in standard mill lengths (typically 12–14 ft) or saw cut to required lengths. For a quote, please visit our Request A Quote page.
Ti-5Al-2.5Sn per MIL-T-9047 flat bar in custom widths and thicknesses in the annealed condition.
Supplied in standard lengths or cut to order for machined structural components. For a quote, please visit our Request A Quote page.
Ti-5Al-2.5Sn per MIL-T-9047 billet (reforging stock) in diameters typically from 3.000″ to 20.000″ and larger, in the annealed condition.
Billet is supplied for forging shop input material where near-net-shape forging is the next operation. For a quote, please visit our Request A Quote page.
Ti-5Al-2.5Sn per MIL-T-9047 die forgings and hand forgings in the annealed condition.
Near-net-shape parts are produced to customer-supplied forging drawings. Provide forging drawing dimensions and quantity for quotation.
For a quote, please visit our Request A Quote page.
What Alloy Types Does MIL-T-9047 Cover?
MIL-T-9047 covers approximately 20 different titanium alloy types and conditions within a single specification document.
This breadth was intentional for the 1950s-era DoD standardization effort, but it creates challenges for modern procurement because a single “MIL-T-9047” callout on a drawing does not identify the specific alloy or condition.
When working with a drawing that calls out MIL-T-9047, engineers must also specify:
which titanium alloy is required (e.g., Ti-5Al-2.5Sn, Ti-5Al-2.5Sn ELI, CP Ti, Ti-6Al-4V, etc.)
annealed or other applicable condition
the specific revision of MIL-T-9047 applicable to the program
Applications of MIL-T-9047 Titanium
Aerospace & Defense Applications
The Ti-5Al-2.5Sn alloy covered by MIL-T-9047 has been used in bar, billet, and forging form in:
- Jet engine structural forgings: Ti-5Al-2.5Sn’s elevated-temperature strength (service to 480°C / 896°F) and superior weldability make bar and forging forms suitable for compressor-section structural components and engine structural fittings
- Aircraft structural machined fittings: round bar for precision-machined attach fittings, brackets, and structural lugs requiring the combination of high specific strength (strength-to-weight ratio), corrosion resistance, and weldability
- Reforging stock and forging billet: large-diameter billet in Ti-5Al-2.5Sn for forging into complex aerospace structural components; billet sourced to MIL-T-9047 requirements for forging shops holding DoD-era procurement requirements
- Cryogenic structural fittings (ELI grade): Ti-5Al-2.5Sn ELI bar is used for structural fittings in cryogenic fuel systems where fracture toughness at liquid hydrogen and liquid oxygen temperatures must be maintained through the full bar cross-section
- Military aerospace structures: bars and forgings for U.S. military aircraft programs during the period when MIL-T-9047 was the active specification; legacy programs still reference this specification on engineering drawings
- Fasteners and precision hardware smaller-diameter round bar for aerospace fasteners, bolts, and precision machined hardware requiring Ti-5Al-2.5Sn properties with DoD specification traceability
MIL-T-9047 Chemical Composition Requirements - Ti-5Al-2.5Sn
MIL-T-9047 specifies chemical composition limits for each alloy type covered within the document.
The following table shows the composition limits for Ti-5Al-2.5Sn in standard and ELI grades as required by MIL-T-9047 and carried forward in the current AMS successor specifications:
| Element | Symbol | Standard Grade (AMS 4924) | ELI Grade (AMS 4926) |
|---|---|---|---|
| Aluminum | Al | 4.0–6.0% | 4.0–6.0% |
| Tin | Sn | 2.0–3.0% | 2.0–3.0% |
| Iron | Fe | 0.50% max | 0.25% max |
| Oxygen | O | 0.20% max | 0.12% max |
| Carbon | C | 0.08% max | 0.08% max |
| Nitrogen | N | 0.07% max | 0.05% max |
| Hydrogen | H | 0.015% max | 0.0125% max |
| Other (each) | - | 0.10% max | 0.10% max |
| Other (total) | - | 0.40% max | 0.40% max |
| Titanium | Ti | Balance | Balance |
Aluminum stabilizes the alpha phase and increases strength at elevated temperatures.
Tin contributes solid-solution strengthening without reducing weldability, which is why Ti-5Al-2.5Sn bars and forgings are preferred over alpha-beta alloys like Ti-6Al-4V when weldability of the machined or forged component is a critical design requirement.
The ELI variant’s reduced interstitial content (particularly oxygen) is specified for bar and forging applications in cryogenic structures where fracture toughness in the bar cross-section must remain adequate at liquid hydrogen and liquid oxygen service temperatures.
Mechanical Properties - MIL-T-9047 Ti-5Al-2.5Sn Bars, Billets & Forgings
Minimum mechanical properties for Ti-5Al-2.5Sn bars and billets in the annealed condition per the applicable AMS successor specifications:
| Property | Standard Grade (AMS 4924) | ELI Grade (AMS 4926) |
|---|---|---|
| Tensile Strength (min) | 115 ksi (793 MPa) | 110 ksi (758 MPa) |
| Yield Strength, 0.2% offset (min) | 100 ksi (690 MPa) | 95 ksi (655 MPa) |
| Elongation in 4D (min) | 10% | 12% |
| Reduction in Area (min) | 25% | 30% |
The ELI grade’s higher minimum elongation and reduction in area requirements reflect its application in fracture-critical bar and forging cross-sections loaded in multiple directions – including cryogenic pressure vessel hardware and structural fittings where cross-sectional ductility in all orientations is a design requirement.
MIL-T-9047 Physical Properties - Ti-5Al-2.5Sn Bars & Forgings
| Property | Value (Imperial) | Value (Metric) |
|---|---|---|
| Density | 0.162 lb/in³ | 4.48 g/cm³ |
| Weight vs. Steel | ~58% the weight of steel | ~58% the weight of steel |
| Modulus of Elasticity | 15.9 × 10⁶ psi | 110 GPa |
| Continuous Service Temperature | Up to 896°F | Up to 480°C |
| Phase Classification | Alpha (single phase) | Alpha (single phase) |
| Heat Treatable? | No | No |
Important clarification
MIL-T-9047 vs AMS-T-9047:
MIL-T-9047 (issued by the U.S. Department of Defense) and AMS-T-9047 (issued by SAE International) are two separate but companion specifications addressing the same product forms.
They are not the same document.
AMS-T-9047 was the SAE version developed in parallel with, and eventually superseding, the MIL-T-9047 designation. Today, both have been superseded by alloy-specific AMS specifications such as AMS 4924 and AMS 4926 for Ti-5Al-2.5Sn bars and billets.
What Replaced MIL-T-9047?
MIL-T-9047 was superseded by individual alloy-specific SAE Aerospace Material Specifications.
The table below shows the primary AMS replacements for the titanium types most commonly ordered against MIL-T-9047 in bar, billet, and forging form:
| Alloy Type (MIL-T-9047) | Common Name | AMS Replacement - Bars, Billets & Forgings |
|---|---|---|
| Ti-5Al-2.5Sn (standard) | Grade 6 Titanium | AMS 4924 |
| Ti-5Al-2.5Sn ELI | Grade 6 ELI Titanium | AMS 4926 |
| Ti-5Al-2.5Sn (additional form) | Grade 6 Titanium | AMS 4966 |
The AMS replacement specifications carry forward the composition and property requirements of MIL-T-9047 while adding enhanced testing, documentation, and qualification requirements aligned with modern AS9100-certified aerospace supply chains.
MIL-T-9047 vs MIL-T-9046 - Key Difference
MIL-T-9047 and MIL-T-9046 are companion military specifications covering different product forms of the same titanium alloy families. They are not interchangeable:
| Characteristic | MIL-T-9046 | MIL-T-9047 |
|---|---|---|
| Product Forms Covered | Sheet, Strip, and Plate | Bars, Billets, and Forgings |
| Issuing Body | U.S. Department of Defense | U.S. Department of Defense |
| First Issued | 1955 | 1955 |
| SAE Counterpart | AMS-T-9046 | AMS-T-9047 |
| Primary AMS Replacements | AMS 4909, AMS 4910 | AMS 4924, AMS 4926, AMS 4966 |
| Cancellation | Scheduled 1999 | Scheduled 1999 |
If your drawing calls out MIL-T-9047, the required product form is bar, billet, or forging.
If it calls out MIL-T-9046, the required product form is sheet, strip, or plate.
MIL-T-9047 and Ti-5Al-2.5Sn - Why This Alloy?
MIL-T-9047 covers approximately 20 titanium alloy types in a single document.
On this site it is catalogued under the Ti-5Al-2.5Sn & ELI section because Ti-5Al-2.5Sn (ASTM Grade 6) is the alloy most commonly procured against MIL-T-9047 for U.S. military aerospace bar and forging applications.
The composition, mechanical property, and material requirements shown on this page reflect MIL-T-9047 as it applies to Ti-5Al-2.5Sn bars, billets, and forgings.
For full alloy data, see the Ti-5Al-2.5Sn & ELI hub page
Why Ti-5Al-2.5Sn Is Preferred for Welded Structures
Ti-5Al-2.5Sn’s all-alpha microstructure provides superior weldability compared to alpha-beta alloys such as Ti-6Al-4V.
For bar and forging components that must be subsequently welded into assemblies – structural fittings, pressure vessel nozzles, and welded structural frames – the alpha alloy heat-affected zone retains adequate strength and ductility without requiring a post-weld stress relief heat treatment.
This significantly simplifies production of welded titanium assemblies that incorporate machined bar components alongside sheet metal elements.
Weldability - MIL-T-9047 Ti-5Al-2.5Sn Bars & Forgings
MIL-T-9047 covers Ti-5Al-2.5Sn, one of the most weldable titanium alloys due to its single-phase alpha microstructure.
Key welding considerations for MIL-T-9047 material in bar and forging form:
- TIG (GTAW): Primary process; argon shielding required for weld pool, back purge, and trailing shield for all fusion welds on Ti-5Al-2.5Sn machined components
- Electron Beam (EBW): Used in vacuum environments for critical aerospace welds where minimum heat input and narrow HAZ are required – particularly applicable to precision machined bar components being welded into engine assemblies
- Post-weld heat treatment: Not required for strength recovery in most applications – a significant advantage over alpha-beta alloys; stress-relief anneal may be applied to reduce residual welding stresses in high-constraint welded assemblies
- Shielding requirement: All titanium welds must be shielded with inert gas (argon or helium) until the weld and heat-affected zone cool below approximately 400°F (204°C) to prevent oxygen and nitrogen embrittlement – this applies to bar-derived machined components during assembly welding
- No transformation hardening: The alpha microstructure does not undergo phase transformation during cooling, so there is no hardened HAZ requiring tempering – a key advantage when welding machined components that will not undergo post-weld heat treatment
- Filler wire: Matching Ti-5Al-2.5Sn ELI filler wire is typically used for all grades, as the ELI filler provides improved HAZ ductility regardless of whether the base metal is standard or ELI grade
Safe Handling of MIL-T-9047 Titanium Bars and Forgings
Titanium bar and forgings in bulk form are safe to handle under normal conditions. Finely divided titanium presents fire and explosion hazards:
- Titanium chips, grinding dust, and fine turnings can ignite above 480°F (250°C) – and in some conditions at lower temperatures if very finely divided
- Use non-chlorinated cutting fluids only – chlorinated fluids can cause stress corrosion cracking in titanium
- Avoid accumulation of chips and fines in machining areas
- Store titanium chips and turnings in closed metal containers
- Use Class D (metal fire) extinguishers for titanium chip/powder fires
- Dry salt (sodium chloride) can smother titanium fires
- Do NOT use water on burning titanium – water can sustain or intensify titanium fires
- Titanium bars can absorb hydrogen during pickling operations – avoid over-pickling; verify hydrogen content per heat certificate (max 0.0150% for standard grade, 0.0125% for ELI)
- Do not use hydrofluoric acid or fluoride-containing cleaning agents unless the process is controlled for titanium; verify hydrogen content after any acid-cleaning operation on bar stock
How to Order MIL-T-9047 Material
MIL-T-9047 is a superseded specification.
When sourcing material against a legacy drawing or program requirement that calls out MIL-T-9047, the following information is needed to source correctly:
which of the ~20 alloy types within MIL-T-9047 is required (e.g., Ti-5Al-2.5Sn, Ti-5Al-2.5Sn ELI, Ti-6Al-4V, CP Ti Grade 2, etc.)
annealed or other condition as specified on the drawing
the specific revision of MIL-T-9047 applicable to your program
round bar (diameter and length), flat bar (width × thickness × length), billet (diameter and length), or forging (provide drawing)
whether material must be certified to the original MIL-T-9047 requirements or to the current AMS equivalent
Fighter Jet Metals can source titanium bars and forgings to current AMS specifications (AMS 4924, AMS 4926, AMS 4966) with documentation showing equivalency to MIL-T-9047 requirements where permitted by program requirements. Contact us with your specification details.
Cross-Reference Specifications for MIL-T-9047
SAE AMS - Ti-5Al-2.5Sn (Standard) Bars & Billets
The primary current AMS replacement for MIL-T-9047 in standard-grade Ti-5Al-2.5Sn bar and billet form – the standard procurement specification for new programs requiring Ti-5Al-2.5Sn long product for machined structural components.
SAE AMS - Ti-5Al-2.5Sn ELI Bars & Billets
The current AMS replacement for MIL-T-9047 in ELI-grade Ti-5Al-2.5Sn bar and billet form – tighter interstitial limits for cryogenic applications where fracture toughness through the full bar cross-section must be maintained at sub-ambient temperatures.
SAE AMS - Ti-5Al-2.5Sn Additional Long-Product Form
Current AMS specification for an additional Ti-5Al-2.5Sn long-product form within the MIL-T-9047 replacement family – covers a specific bar, billet, or ring product form. Verify the exact form coverage against the current revision of AMS 4966 for procurement.
Companion Specification - Sheet, Strip & Plate
MIL-T-9046 is the companion military specification covering the same titanium alloy families as MIL-T-9047 but in the flat-rolled product forms of sheet, strip, and plate. Not a cross-reference for the bar/forging product form, but listed here as the companion spec for programs that require both sheet and bar product forms of Ti-5Al-2.5Sn under DoD-era drawings.
MIL-T-9047 Trade Names & Equivalent Designations
MIL-T-9047 and the Ti-5Al-2.5Sn alloy it covers in bar and forging form are referenced under several designations across different standards systems:
| Designation | System | Notes |
|---|---|---|
| Ti-5Al-2.5Sn | Common alloy name | Most widely used international notation |
| Grade 6 Titanium | ASTM designation | Per ASTM B265 and ASTM B348 classification |
| ASTM Grade 6 | ASTM formal | Used in ASTM B348 (bar) and B381 (forgings) |
| UNS R54520 | UNS (Unified Numbering System) | Standard material identifier in North America |
| Alpha Titanium | Phase classification | Describes single-phase microstructure |
| Ti-5-2.5 | Shorthand | Used in aerospace sourcing and engineering |
| 5Al-2.5Sn | Composition shorthand | Common in aerospace procurement documents |
| Ti-5Al-2.5Sn ELI | ELI variant | Extra Low Interstitial - tighter O, Fe, N, H limits |
| AMS 4924 | SAE specification | Current AMS equivalent for standard-grade bars |
| AMS 4926 | SAE specification | Current AMS equivalent for ELI-grade bars |
| AMS-T-9047 | SAE specification | SAE counterpart to MIL-T-9047 |
| AMS 4966 | SAE specification | Current AMS equivalent for additional Ti-5Al-2.5Sn long-product form |
Why Source MIL-T-9047 from Fighter Jet Metals?
Legacy program expertise
MIL-T-9047 is a superseded specification. We understand how to source material to legacy program requirements and provide documentation showing equivalency to current AMS standards (AMS 4924, AMS 4926, AMS 4966) where applicable
Full mill certifications on every order
heat number, lot number, chemical analysis, and mechanical test certifications provided with each shipment
Billet and forging supply
reforging stock billet and customer-drawing forgings available; provide forging drawing for quotation
Complete heat-lot traceability
full chain of custody from mill to delivery
Aerospace-grade sourcing
material from AS9100-certified mills only
Both standard and ELI grades available
Ti-5Al-2.5Sn standard grade and ELI grade bars, billets, and forgings stocked and available for same-day quote
Rapid quote response
competitive pricing with same-day quote turnaround
Custom processing
saw cutting and custom bar lengths available
Certified Material for Critical Service
Aerospace programs demand strict adherence to recognized material standards and OEM specifications. Fighter Jet Metals supplies 5Al-2.5Sn & ELI titanium in accordance with AMS, MIL, and major aerospace company specifications, including those used by Boeing and other aerospace manufacturers.
All material is delivered with full mill certification, heat-lot traceability, and supporting documentation to meet the quality and compliance requirements of aerospace, defense, and high-performance industrial programs.