ASTM F136 Ti-6Al-4V ELI Grade 23 Titanium Wire
- Standard: ASTM F136 (or contract-specified edition)
- Grade: Ti-6Al-4V ELI (Grade 23)
- UNS: R56401
- Supply form: Coil, spool or cut straight length
- Condition: Annealed, as ordered
- Diameter Range: Ø0.03–Ø7.0 mm
Customizable sizes are available, while specific product parameters should be confirmed per the applicable standard edition and order.
Product Overview
ASTM F136 Ti-6Al-4V ELI (commonly called Grade 23) titanium wire is wrought, annealed alpha-beta titanium alloy wire for surgical implant manufacture, UNS R56401. ELI means extra-low interstitial. Compared with conventional Ti-6Al-4V, tighter limits on oxygen, iron and other interstitial elements improve fracture toughness, fatigue-crack-growth resistance and low-temperature toughness while retaining high specific strength, corrosion resistance and good biocompatibility.
Wire may be supplied in coils, on spools, or as cut straight lengths. Typical uses include orthopedic fixation components, dental and cranio-maxillofacial devices, surgical instruments and precision medical parts. ASTM F136 specifies medical-alloy raw material; the finished implant still requires device-level validation for actual diameter, cold work, microstructure, surface integrity, fatigue, cleaning, sterilization, biological evaluation and applicable regulation.
| Specification | Details |
| Industrial Standard | ASTM F136 |
| Grades | Ti-6Al-4V ELI (Grade 23) |
| Diameter Range | Ø0.03–Ø7.0 mm |
| Typical Diameters | Ø0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.8, 1.0, 1.2, 1.5, 2.0, 2.5, 3.0, 4.0, 5.0, 6.0, 7.0 mm |
| Supply Form | Coil / Spool or straightened and cut wire |
Medical-use boundary: ASTM F136-compliant wire is medical-device raw material, not an approved finished implant. The device manufacturer remains responsible for design, forming/joining, surface treatment, cleaning, sterilization, biological evaluation, risk management and regulatory compliance.
Main Characteristics
- Medical Ti-6Al-4V ELI: Tight control of oxygen, iron, carbon, nitrogen and hydrogen improves damage tolerance while preserving the high strength of Ti-6Al-4V, suiting devices sensitive to fatigue, bending and fracture.
- Controlled alpha-beta chemistry: Aluminum stabilizes alpha and vanadium stabilizes beta. Al, V, interstitials and residual elements require heat-specific control for consistent strength, ductility, microstructure and drawing response.
- Good biocompatibility: A stable TiO2 passive film and extensive clinical use support its role as a common implant material. The finished device still requires biological evaluation under applicable regulations and standards such as ISO 10993.
- Good corrosion resistance: Performance is generally excellent in saline, body fluids and many chloride environments, but fretting, crevices, dissimilar-metal coupling, fluoride media and surface contamination require device-level evaluation.
- Weldable with strict shielding: Qualified laser, resistance, electron-beam or GTAW/TIG processes may be used. The pool, root and hot heat-affected zone require full inert-gas protection. Fine-wire joining must also control local melting, heat-affected-zone embrittlement and dimensional distortion.
- High strength with limited cold formability: The alloy can be drawn, straightened, coiled and cold-bent to a limited extent, but has less room-temperature forming margin and greater springback than unalloyed titanium. Performance depends on diameter, annealed condition and residual cold work; complex forming requires qualified bend radii and, where necessary, intermediate annealing.
Chemical Composition
The following mass-percent limits are commonly applied to ASTM F136 Ti-6Al-4V ELI (UNS R56401). The current active edition is ASTM F136. Formal purchasing and acceptance are governed by the contract edition, official ASTM text and original mill report. The standard includes a hydrogen note for small-section material, shown below.
| Element | ASTM F136 Ti-6Al-4V ELI requirement |
| Nitrogen, N | ≤0.05% |
| Carbon, C | ≤0.08% |
| Hydrogen, H | ≤0.0125%* |
| Iron, Fe | ≤0.25% |
| Oxygen, O | ≤0.13% |
| Aluminum, Al | 5.5-6.5% |
| Vanadium, V | 3.5-4.5% |
| Residual elements, each | ≤0.10% |
| Residual elements, total | ≤0.40% |
| Titanium, Ti | Balance |
- * For material 0.813 mm (0.032 in) and under, hydrogen may be up to 0.0150%; the contract-specified ASTM edition governs.
- Technical references: ASTM F136 official scope, established technical data from ASTM F136-13(2021)e1, and published data from specialist medical-wire producers.
- Aluminum and vanadium: Al is 5.5-6.5% and V is 3.5-4.5%, together producing a heat-treatable alpha-beta microstructure. Chemical homogeneity, melting and thermomechanical processing affect microstructure and final properties.
- Oxygen, iron and interstitials: Lower O, Fe, C, N and H limits improve toughness and fatigue-crack-growth behavior. For material 0.813 mm (0.032 in) and under, the standard note permits hydrogen up to 0.0150%; other sizes commonly use 0.0125% maximum. Confirm the applicable contract edition and actual diameter.
- Residual elements: Each and total limits must be controlled. The material report must correspond to the heat; testing only Al and V does not satisfy the complete chemistry requirement.
- Titanium content: The specification states Titanium: Balance. A nominal grade or medical-grade claim does not replace heat-specific analysis, the material report and contract testing.
Mechanical Properties
ASTM F136 specifies room-temperature tensile requirements for annealed wrought Ti-6Al-4V ELI. Common annealed-wire reference minimums are 860 MPa ultimate tensile strength, 795 MPa 0.2% offset yield strength and 10% elongation. Acceptance must follow the actual diameter, specimen form, gauge length, orientation and official table in the contract edition; cold-drawn typical strength must not be substituted for annealed ASTM F136 acceptance values.
| Property | ASTM F136 annealed reference | Note |
| Ultimate tensile strength | ≥860 MPa | Specified minimum |
| 0.2% yield strength | ≥795 MPa | Specified minimum |
| Elongation | ≥10% | Gauge length/specimen requirements follow the contract edition |
ASTM F136 Ti-6Al-4V ELI Annealed Wire Reference Requirements
| Property | Ti-6Al-4V ELI annealed reference |
| Ultimate tensile strength | Minimum 860 MPa |
| 0.2% yield strength | Minimum 795 MPa |
| Elongation | Minimum 10% |
| Elastic modulus | Typical approx. 105-116 GPa |
Important: Mechanical properties must be applied with actual diameter, specimen form, gauge length, orientation, annealed condition and the official table. Fine-wire testing may require specialized gripping and elongation measurement. Generic web data cannot replace contract acceptance, and ASTM F136 raw-material compliance alone does not approve a finished implant.
HTN Supply and Quality Documentation
HTN organizes ASTM F136 Ti-6Al-4V ELI (Grade 23) medical titanium wire supply to customer purchase requirements. Material is produced by qualified titanium-mill resources. Original mill reports, heat/coil traceability, chemistry and mechanical records can be supplied as agreed. HTN reviews the standard edition, diameter, tolerance, condition, surface, straightness or coil requirements, weld restrictions and packaging, and can arrange independent retesting, microstructure examination, eddy-current or applicable surface-continuity testing, cutting, clean packaging and third-party inspection.
Typical Applications
- raw material for orthopedic cerclage wire, fixation systems and tension-band components;
- fine-diameter fixation or connecting components in spinal, trauma, cranio-maxillofacial and dental devices;
- surgical suturing, anchoring, elastic or precision connecting components, subject to device-design validation;
- medical wire stock for precision machining, coiling, braiding or forming;
- medical-device parts requiring high specific strength, good damage tolerance and corrosion resistance;
- coil, spool, cut-straight and precision-finished wire supplied to customer drawings;
- medical-device research, prototypes and custom implant material;
- international projects when ISO 5832-3, regulatory and customer supplementary requirements are also met.
Application boundary: ASTM F136 Ti-6Al-4V ELI wire is raw material for surgical implant applications, not an approved finished implant. The final device must separately meet applicable regulations, design validation, fatigue evaluation, biological evaluation, cleaning, sterilization and traceability requirements.
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Fabrication and Machining Characteristics
Drawing, Finishing and Dimensional Control
Ti-6Al-4V ELI wire is commonly made by qualified melting, ingot breakdown, wire-rod rolling, multiple cold- or warm-drawing passes, intermediate annealing where needed, final annealing, straightening and surface finishing. Pass reduction, die condition, lubrication, tension and temperature must be controlled to limit internal defects, laps, scratches, diameter variation, residual stress and within-lot variation.
Coiling, straightening and forming
Wire may be supplied in coils, on spools or as cut straight lengths. Straightening and coiling response depends on diameter, annealed condition, surface quality and residual cold work. Coil mandrel, repeated bending and device-forming processes should be qualified on the actual lot to avoid tight-radius cracking, tool damage and excessive local work hardening.
Annealing and heat treatment
ASTM F136 fundamentally applies to annealed material. Wire production may use intermediate anneals to restore ductility and a controlled final anneal to achieve specified properties. Temperature, soak, cooling and vacuum/inert atmosphere must be controlled to avoid grain coarsening, excessive beta transformation, alpha case, oxidation and hydrogen pickup. Cold-worked or special conditions require separate contract definition and validation.
Welding and joining
Qualified laser, resistance, electron-beam or GTAW/TIG joining may be used. Remove oil, oxides and drawing residue before joining and fully shield hot metal. Because fine-wire welds have concentrated thermal cycles, the finished device must validate joint microstructure, strength, fatigue, corrosion resistance and cleanliness.
Typical Physical Properties
The following are typical values for annealed Ti-6Al-4V ELI near room temperature. Unless explicitly required by the standard or contract, they are not mandatory ASTM F136 lot-acceptance values.
| Physical property | Reference value |
| Density | Approx. 4.43 g/cm³ |
| Elastic modulus at room temperature | Approx. 105-116 GPa |
| Thermal conductivity at room temperature | Approx. 6.7 W/(m·K) |
| Mean CTE, 20-100°C | Approx. 8.6×10⁻⁶/K |
| Solidus/liquidus reference | Approx. 1604-1660°C |
| Poisson’s ratio | Typically approx. 0.34 |
| Crystal structure at room temperature | Alpha + beta |
| Magnetism | Essentially non-magnetic |
| Strengthening mechanism | Solid solution, microstructure control and optional heat treatment |
| Specific heat at room temperature | Typically approx. 526 J/(kg·K) |
Physical-property reference: Producer data for Ti-6Al-4V ELI / UNS R56401. Values vary with temperature, microstructure, orientation, cold work and heat treatment and are not routine ASTM F136 lot-acceptance values.
Korrosionsbeständigkeit
Ti-6Al-4V ELI develops a spontaneous, renewable TiO₂ passive film and generally resists saline, body fluids and many aqueous chlorides. Wire performance also depends on surface scratches, drawing-lubricant residue, micromotion, fretting, crevices, dissimilar metals, electrochemical conditions, bending residual stress and cleaning or sterilization residue.
Environments in Which Grade 23 Generally Performs Well
- Saline and many simulated-body-fluid environments;
- humid air and high-purity water;
- neutral chloride solutions;
- many oxidizing environments;
- properly controlled cleaning and passivation processes;
- many medical-device sterilization processes after device validation;
- long-term tissue contact without fretting;
- validated orthopedic, spinal and dental implant environments.
Environments Requiring Careful Evaluation
- Fluoride cleaners, hydrofluoric acid or high-fluoride oral conditions;
- local acidification in oxygen-starved crevices;
- combined fretting, wear and corrosion;
- galvanic coupling with unsuitable dissimilar metals;
- cathodic hydrogen charging or improper electrochemical treatment;
- strong reducing acids;
- hot concentrated salts or unusual disinfection chemicals;
- areas containing particles, residues or surface damage;
- new uses lacking device-level corrosion and biological validation.
Engineering caution: Biocompatibility, fatigue and body-fluid corrosion performance are not determined by grade alone. Wire cleanliness, microstructure, surface scratches, drawing residue, residual stress, cold work, micromotion, wear, crevices, dissimilar metals, fluoride exposure and sterilization residue can affect the final device.
Typical Industry Manufacturing Route for ASTM F136 Ti-6Al-4V ELI Titanium Wire
- Raw-material selection and charge preparation: Use qualified titanium raw material, aluminum-vanadium master alloy and strictly controlled clean revert, closely controlling O, Fe, C, N, H and residual elements.
- Electrode preparation: Homogenize, compact and weld consumable electrodes while avoiding high-density inclusions, low-density inclusions, oil, moisture and foreign contamination.
- Melting and ingot production: Use a qualified vacuum-melting route meeting ASTM F136 and purchase requirements, controlling chemistry uniformity, inclusions and ingot quality. Melt count and special raw-material restrictions are governed by the standard and order.
- Ingot conditioning and wire-rod rolling: Crop unsuitable ends, remove surface defects, break down the cast structure by forging/rolling, then roll to wire rod suitable for drawing.
- Drawing and intermediate annealing: Draw through multiple passes with controlled dies, lubrication, tension, pass reduction and temperature. Use intermediate annealing where needed to restore ductility and control microstructure and residual stress.
- Final annealing and surface conditioning: Apply a qualified final anneal; remove scale, alpha case and drawing residue; prevent hydrogen pickup and iron contamination; and achieve the ordered annealed microstructure, properties and clean surface.
- Straightening, coiling and finishing: Supply cut straight lengths, coils or spools as ordered, controlling diameter, tolerance, roundness, straightness/cast, surface roughness, weld count and coil weight.
- Cleaning: Use validated mechanical or chemical cleaning to prevent oil, abrasive, iron, chlorinated-cleaner and pickling residue. Final implant precision cleaning and sterilization remain the device manufacturer responsibility.
- Inspection: Verify chemistry, tensile properties, diameter, surface and identification by heat or lot. Microstructure, eddy-current testing, wire continuity, straightness, roughness or other supplementary examinations follow the standard and order. Ultrasonic testing is not a universal method for all fine wire.
- Identification, packaging and traceability: Maintain one-to-one correspondence among heat, lot, coil/spool, wire and report. Use clean, dry, scratch-resistant packaging to prevent tangling, mix-ups and cross-contamination.
Manufacturing and inspection note: ASTM F136 specifies material requirements, but diameter and tolerance, supplementary melting requirements, coil/spool/straight form, weld restrictions, straightness or cast, roughness, continuity testing, clean packaging, EN 10204 3.1 documentation and third-party inspection must be confirmed in the purchase order.
