Why Ti-6Al-4V dominates aerospace and medical
Titanium Grade 5 (Ti-6Al-4V) is ~55% of all titanium sold globally because it hits a sweet spot no other alloy reaches: strength comparable to steel at 45% less weight, excellent corrosion resistance, and biocompatibility good enough for permanent implants. The trade-off is cost — raw stock is roughly 7× more expensive than 6061 aluminum, and machining speeds are 10× slower. But when the application demands the strength-to-weight ratio, corrosion resistance in body fluids, or temperature performance up to 400 °C, nothing else substitutes.
Our typical Ti-6Al-4V customer is running aerospace structural brackets (20–200 pieces per lot), medical device components (10–500 pieces with ELI Grade 23 stock), or high-performance bicycle and motorsport parts (50–2,000 pieces with anodized finish). The common thread: they need full traceability from mill to finished part, documented tolerance capability, and process control they can audit.
Standard Grade 5 vs ELI Grade 23 — which one do you need
Standard Ti-6Al-4V (AMS 4928) is specified for aerospace structural parts, industrial components, marine fasteners, and anything that doesn't touch the human body. It's ~10–15% cheaper than ELI and easier to source in common bar and plate sizes. ELI (Ti-6Al-4V ELI, AMS 4930 or ASTM F136) restricts oxygen to 0.13% maximum, which improves fracture toughness — essential for orthopedic implants subjected to repeated cyclic loading, and for cryogenic aerospace applications like pressure vessels and fuel-system components.
If your drawing calls out "Ti Grade 5" or "Ti-6Al-4V" without specifying ELI, we assume standard Grade 5 per AMS 4928. If there's any implant or cryogenic application in play, specify "Grade 23" or "AMS 4930" or "ASTM F136" explicitly — we'll source the correct stock and provide the matching certification. See the titanium materials page for full stock data.
Machining parameters — why titanium wants its own playbook
Titanium has three properties that punish inexperienced machinists: low thermal conductivity (heat goes into the tool instead of the chip), work-hardening (wrong feed rate creates a hardened skin that destroys the next pass), and reactivity (hot chips weld themselves to the cutting edge). We run Ti-6Al-4V at conservative parameters — ~40 m/min surface speed for roughing, 60 m/min for finishing, feed per tooth ~0.05 mm, aggressive flood coolant at 20–40 bar through-spindle.
For pocket milling, we use climb-cut exclusively — conventional milling work-hardens the next tooth engagement. For drilling, we peck every 0.5–1.0 diameter to clear chips and prevent built-up edge. Our aerospace-grade 5-axis machines (DMG MORI DMU 65 monoBLOCK) run with adaptive toolpath in Mastercam to keep chip load consistent, which is the single biggest factor in getting predictable tool life on titanium.
5-axis for structural brackets, Swiss for fasteners and pins
Aerospace structural brackets with compound geometry and critical GD&T run on our 5-axis machines — typical envelope 600 × 400 × 400 mm, typical cycle time 45 minutes to 4 hours depending on complexity. For high-volume smaller parts (fasteners, bushings, pins, small brackets up to 32 mm diameter), we run dedicated Swiss-turn machines with live tooling, which hold tight cylindrical tolerances and allow full complex machining in one operation. For parts between these ranges, 3-axis VMC with 4th-axis rotary is usually the most cost-effective.
Inspection, certification, and documentation
Every Ti-6Al-4V batch includes: full-dimensional first-article inspection (FAI) against your drawing with CMM data for GD&T features, in-process SPC on critical dimensions, mill certificates per AMS 4928 or ASTM B348 linked to your PO by heat number, chemistry and mechanical property reports, and Certificate of Conformance. For aerospace customers, we add AS9100-aligned documentation including process travelers, tool validation records, and non-conformance tracking. For medical ELI work, we add ASTM F136 biocompatibility statements and full supply-chain traceability from mill through our facility. See the quality control process page for complete scope.
Finish options — anodize, passivate, or as-machined
Default finish is as-machined Ra 0.8–1.6 µm, which is fine for most aerospace structural parts and all medical components going to customer finishing. For identification and corrosion improvement, we offer sulfuric-anodize (Type II, AMS 2488) in six standard colors (blue, gold, bronze, purple, green, pink) — common on aerospace bracketry and premium bicycle components. For adhesive bond prep, chromic-anodize (Type I) provides the best primer adhesion. Passivation per AMS 2700 removes free iron contamination and is standard on any medical-adjacent component even when the customer plans to do final finishing themselves.
What to send for a Ti-6Al-4V quote
Required: STEP file, PDF drawing with tolerances and material callout (Grade 5, Grade 23, specific mill spec like AMS 4928), target quantity, and target delivery date. Helpful: GD&T on critical features, surface finish callouts, specific mill spec required for certification, AVL constraints (if we need to route through a specific AS9100 partner), and packaging requirements (ESD, individual wrap, heat-treat fixture compatibility). For repeat customers, we keep your typical material and spec profile on file so repeat quotes come back within hours.