Titanium Alloy Grades Guide — Selection Reference for Engineers
Authoritative reference covering all commercially significant titanium grades — from CP Grades 1-4 through aerospace Ti-6Al-4V, medical Grade 23 ELI, and specialty corrosion-resistant alloys Grade 7 and Grade 12. Each entry includes nominal chemical composition, tensile and yield strength, machinability rating, and core industrial application nodes.
Commercially Pure (CP) Titanium grades operate as unalloyed alpha-phase crystal structures, where mechanical properties are tightly governed by the calibrated interstitial containment of iron and oxygen. Grade 1 exhibits maximum cold formability for deep-drawn cryogenic frameworks, while Grade 2 serves as the absolute workhorse for global subsea oceanographic infrastructure. The supreme resistance of CP titanium against localized chloride pitting and galvanic stress corrosion is due to its instantaneous passivation, creating a permanent, self-healing Titanium Dioxide (TiO₂) protective film upon atmospheric exposure.
When CNC machining Grade 2 fluid manifolds, the primary engineering challenge is managing its extreme ductility and "gummy" material behavior. BOZE overcomes this by utilizing ground, highly polished carbide inserts with razor-sharp cutting edges to cleanly shear the material, successfully preventing material adhesion, tearing, and micro-burr generation across intricate marine sealing surfaces.
Representing more than 50% of the entire global titanium market volume, Grade 5 (Ti-6Al-4V) is a fully heat-treatable alpha-beta alloy engineered for supreme structural performance under cyclic fatigue loading. Possessing an ultimate tensile strength exceeding 895 MPa, it delivers an unmatched strength-to-weight ratio across temperature spectrums up to 400°C.
Machining Grade 5 brackets and drone rotor hubs requires high-rigidity 5-Axis Machining Centers to suppress structural chatter. The material's rapid work hardening mechanism demands that cutting tools never rub; BOZE engineers lock down toolpaths with an absolute minimum feed per tooth of 0.08 mm. We employ PVD-coated AlTiN multi-layer tools, executing advanced high-feed trochoidal milling toolpaths that run at a controlled radial step-over (aₑ) of 5% to 8%, keeping tool edge temperatures below the catastrophic diffusion phase threshold.
Grade 23 ELI — Ultra-Pure Interstitial Bio-Gating for Orthopedic Hardware
Grade 23 ELI (Ti-6Al-4V Extra Low Interstitials) stands as the ultra-purified chemical variant of Grade 5, where interstitial gas elements are severely restricted: Oxygen is capped at ≤ 0.13% and Iron at ≤ 0.25%. This molecular refinement dramatically upgrades fracture toughness at cryogenic ranges and ensures absolute biocompatibility for human tissue integration.
BOZE processes Grade 23 ELI utilizing multi-axis CNC Swiss Lathes to manufacture critical orthopedic bone screws, dental implant abutments, and internal trauma plates. To protect the component matrix from cross-contamination, we enforce a strict zero-hydrocarbon production boundary. This involves running specialized synthetic ester cutting oils and conducting a mandatory multi-stage deionized water ultrasonic cleaning lifecycle to clear all organic micro-residues, achieving flawless compliance with rigid biomedical bio-burden and cytotoxicity validation standards.
Grade 7 & Grade 12 — Severe Chemical Processing & Pitting Defense Systems
Designed explicitly to survive severe, highly localized crevice corrosion in chemical processing plants, Grade 7 integrates 0.12% to 0.25% Palladium (Pd), making it the most corrosion-resistant titanium alloy available for reducing acid exposures. Grade 12 incorporates 0.3% Molybdenum and 0.8% Nickel, providing an economical, high-strength alternative that resists hot chloride crevice attacks up to 300°C.
BOZE machines these specialized alloys into high-pressure chemical reactor valves, fluid manifolds, and severe-service petrochemical mixing agitators. Processing these alloys demands precision thread chasing and internal channel pocketing. We implement dynamic CAM toolpaths to hold a continuous internal surface finish of Ra ≤ 0.4 µm, completely removing any micro-geometric stagnation nodes where aggressive corrosive fluids could accumulate.