Why titanium, and when not to
Titanium Grade 5 (Ti-6Al-4V) combines the strength of mid-grade steel with roughly 60% of its weight, plus exceptional corrosion resistance and biocompatibility. Those three properties make it the default for orthopedic implants, aerospace structural fasteners, and high-end sporting goods. They also make it 5–10× more expensive to produce finished parts in than aluminum, which is why titanium is specified sparingly.
Before we machine titanium, our engineers typically ask: could 7075 aluminum work? Could 17-4 PH stainless work? Titanium wins when the answer to both is no — when you need strength-to-weight that aluminum can't deliver, corrosion performance that stainless can't match, or biocompatibility for implants.
Grade 5 vs Grade 23 — the medical split
The chemistry of Grade 5 and Grade 23 (Ti-6Al-4V ELI) differs only in interstitial element limits — oxygen, nitrogen, carbon, and iron are held to tighter maximums in Grade 23. The resulting mechanical difference is subtle: Grade 23 has about 10% better fracture toughness and fatigue performance, at the cost of about 5% lower yield strength.
For permanent orthopedic implants (hip stems, bone screws, spinal cages), Grade 23 is the regulatory default under ASTM F136. For trial implants, surgical instruments, non-load-bearing medical parts, and virtually all aerospace applications, Grade 5 per ASTM F1472 or ASTM B348 is adequate and significantly cheaper.
Aerospace and structural applications
We machine titanium aerospace brackets, engine mount components, and hydraulic system fittings to AS9100-aligned process controls. The cost premium over aluminum is worth it when: (1) operating temperature exceeds 200 °C (aluminum loses strength rapidly above this), (2) weight savings of 40% justify the material cost, or (3) galvanic corrosion in contact with stainless fasteners rules out aluminum.
For large structural aerospace parts, we recommend titanium plate rather than billet — plate is hot-worked and has better grain structure. For small high-detail parts, 5-axis machining from billet makes more sense. Our 10 Beijing Jingdiao JD500 5-axis centers handle titanium up to roughly 300 × 300 × 150 mm envelope.
Finishing — color and passivation
The colored "anodize" you see on titanium surgical instruments and custom bike parts is actually electrochemical oxide growth, not aluminum-style dye anodize. By varying voltage from 10 V to 100 V, we produce gold, bronze, purple, blue, teal, and pink — repeatably within one batch, less repeatably across lots.
For medical implant finishing, we passivate to ASTM F86 in nitric acid or citric acid (per customer requirement), which removes surface iron contamination and grows a clean, uniform TiO₂ passivation layer. Bead blast before passivation gives a uniform matte finish that hides handling marks.
Cost expectations
Raw Ti-6Al-4V billet runs roughly 6× the per-kilogram cost of aluminum 6061. Machine time is typically 2–3× longer per part. Tooling wear is 3–5× faster. Net result: a CNC part in titanium costs about 5× the same part in aluminum. For prototype quantities below 10 pieces, wire EDM from plate is sometimes cheaper than 3-axis milling from billet — we'll flag this during DFM review if it applies to your geometry.
Lead time is typically 7–14 days for titanium parts versus 3–7 days for aluminum. If your project requires Grade 23 medical-grade stock, add 1–2 weeks for sourcing from certified mills (ATI Specialty Alloys, TIMET, Baoji Titanium).