Ti-6Al-4V (Grade 5) vs 6061-T6
Ti-6Al-4V and 6061-T6 aluminum are the workhorse alloys when a part must be both light and strong, but they sit at opposite ends of the cost-versus-performance scale. The right pick depends on whether weight and environment justify titanium's price and machining pain.
The verdict
Choose Ti-6Al-4V when the part is weight- and strength-critical, fatigue-loaded, runs hot, or lives in seawater, chlorides, or the body — and the budget can absorb titanium's cost and slow machining. Choose 6061-T6 aluminum for most general structural, enclosure, and high-volume work, where its low cost, easy machining, good weldability, and great anodizing deliver far better overall value.
Side-by-side data
| Property | Ti-6Al-4V (Grade 5) | 6061-T6 |
|---|---|---|
| Category | Titanium | Aluminum |
| Density (g/cm³) | 4.43 | 2.7 |
| Tensile strength (MPa) | 1000 | 310 |
| Yield strength (MPa) | 910 | 276 |
| Elongation (%) | 14 | 12 |
| Hardness | 36 HRC | 95 HB |
| Max service temp (°C) | 400 | 170 |
| Machinability | ●●●●● | ●●●●● |
| Corrosion resistance | ●●●●● | ●●●●● |
| Relative cost | ●●●●● | ●●●●● |
| Thermal cond. (W/m·K) | 6.7 | 167 |
| Typically used for | Aerospace & medical — best strength-to-weight | All-round structural & machined parts — the default aluminum |
Which should you choose?
Choose Ti-6Al-4V if…
- The part is weight- and strength-critical and aluminum can't hit the load target without bulking up
- It's fatigue-loaded — titanium's endurance limit and high specific strength pay off in cyclic service
- It runs hot (roughly 150-400°C), where 6061-T6 loses its temper and goes soft
- It sits in seawater, chlorides, or a biological/implant environment where titanium is essentially immune
- It must be galvanically compatible with carbon-fiber structures to avoid driving corrosion
Choose 6061-T6 Aluminum if…
- Cost and lead time drive the program — material and machining are a fraction of titanium's
- You're machining at volume; 6061-T6 cuts fast with long tool life, while Ti-6Al-4V is slow, hot, and tool-hungry
- You need to weld the part — 6061 welds readily (4043/5356 filler), Ti requires full inert shielding and clean discipline
- Thermal or electrical conductivity matters (heat sinks, bus bars, enclosures)
- You want easy, durable anodizing for cosmetics or wear
Key differences that matter
- Strength-to-weight: Ti-6Al-4V is far stronger and ~1.7x denser than aluminum, so per unit weight titanium wins decisively — but 6061-T6 is cheaper per usable unit of strength on non-weight-critical parts.
- Machinability is the biggest hidden cost driver: 6061-T6 is among the easiest alloys to cut, while Ti-6Al-4V is gummy, work-hardening, and low-conductivity, often running 5-10x the machining cost.
- Temperature: 6061-T6 begins losing temper above ~150°C and is unusable structurally past ~200°C; Ti-6Al-4V holds useful strength to roughly 300-400°C.
- Corrosion: both resist atmosphere, but titanium is essentially immune in chlorides, seawater, and the body, while aluminum needs anodizing/coatings and is prone to pitting and galvanic attack.
- Weldability and cost favor aluminum: 6061 welds with standard gear (with some HAZ softening), whereas titanium needs full inert-gas shielding and costs many times more finished.
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Open the Material SelectorGet a Quote →Frequently asked questions
Is Ti-6Al-4V stronger than 6061-T6 aluminum?
Yes, substantially — in both absolute strength and strength-to-weight. Titanium is denser, but its much higher strength lets a titanium part be lighter than aluminum for the same load, which is exactly why aerospace pays the premium.
Which is cheaper?
6061-T6 aluminum, by a wide margin. The raw metal is several times cheaper per pound, and because aluminum machines far faster with longer tool life, the finished-part gap is even larger. Titanium only pays off when weight or environment demands it.
Can I weld and anodize each one?
6061 welds easily with common TIG/MIG setups (expect some heat-affected-zone softening) and anodizes well. Titanium can be welded but needs thorough inert-gas shielding to avoid embrittlement, and anodizes mainly for color rather than the thick protective layer aluminum gets.
Which machines more easily?
6061-T6, decisively — it's a benchmark for good machinability with fast feeds and long tool life. Ti-6Al-4V work-hardens, holds heat at the cutting edge, and needs slow speeds, rigid setups, and frequent tool changes, driving up cost and time.
When does titanium actually justify its cost over aluminum?
When the part is weight- and strength-critical, fatigue-loaded, runs hot (above ~150-200°C), sits in seawater or chlorides, contacts the body, or must be galvanically compatible with carbon fiber. Outside those cases, 6061-T6 usually delivers better overall value.
Property values are typical/nominal figures for early-stage guidance only and vary by temper, grade, supplier and heat treatment. Confirm critical specifications against a certified datasheet or with an mfgiq engineer before production.