COMPREHENSIVE TECHNICAL ANALYSIS AND DATASHEET OF TITANIUM GRADE 23 (Ti-6Al-4V ELI) FASTENERS

Titanium Grade 23 (UNS R56401), universally recognized as Ti-6Al-4V ELI (Extra Low Interstitial), is the ultimate high-purity variant of the aerospace-standard Grade 5. By taking the proven Aluminum-Vanadium matrix and severely restricting the interstitial elements—specifically driving Oxygen down below 0.13% and capping Carbon and Iron—the metallurgical profile undergoes a profound shift. The alloy sacrifices a tiny fraction of its ultimate tensile strength to achieve a massive leap in fracture toughness, ductility, and fatigue resistance.

Because of its hyper-pure composition, Grade 23 avoids the embrittlement that standard titanium alloys experience at ultra-low temperatures, retaining its mechanical integrity down to cryogenic levels (-253°C). Furthermore, its flawless biocompatibility, absolute immunity to bodily fluids, and superior damage tolerance make UNS R56401 fasteners the undisputed, globally mandated standard for mission-critical surgical implants, deep-space cryogenic propulsion systems, and extreme offshore environments.

In surgical and aerospace environments, a fraction of a percent of excess oxygen can cause catastrophic brittle failure. Ananka ensures that every Grade 23 fastener is backed by rigorous Vacuum Arc Remelting (VAR) certification, guaranteeing its Extra Low Interstitial status.

• EN 10204 Type 3.1: Validates the critical 0.13% maximum Oxygen limit, certifies the precise Aluminum-Vanadium stabilization, and confirms the annealed mechanical properties required for deep-drawing or severe loading.
• EN 10204 Type 3.2: Available upon request for orthopedic implant manufacturing, NASA/ESA space flight hardware, and cryogenic natural gas handling facilities requiring independent third-party oversight.

The "ELI" designation is the defining characteristic of this alloy. While standard Grade 5 allows up to 0.20% Oxygen and 0.40% Iron, Grade 23 violently restricts these interstitial elements. This hyper-purity dramatically increases the metal's ductility and its resistance to crack propagation under cyclic stress.

• Biomedical & Surgical: The absolute gold standard for orthopedic bone screws, maxillofacial plates, spinal fusion hardware, and dental implants requiring flawless osseointegration and fatigue resistance.
• Aerospace & Space Exploration: High-stress structural fasteners for rocket propulsion systems and cryogenic fuel tanks where the metal must survive extreme temperature gradients without shattering.
• Deep-Sea & Marine: Submersible pressure vessel housings and specialized subsea rigging where the fracture toughness of Grade 23 outperforms the more brittle Grade 5.

While Grade 23 provides incredible strength, its high purity and reactive surface oxide make it notoriously prone to severe thread galling (cold-welding). For industrial applications, aerospace-grade anti-seize pastes are mandatory. For medical implant applications, specialized inert biomedical lubricants or careful, low-speed manual torquing must be utilized to prevent seizing.