# Titanium vs Aluminum for Aerospace and Medical Parts: How to Choose > Ti-6Al-4V and Grade 2 titanium compared with 6061-T6, 7075-T6 and 2024-T4 aluminum on strength, density, specific strength, machining speed and real cost, with a decision table for drawings. https://www.sinbo-machining.com/blog/titanium-vs-aluminum/ --- ## On This Page - Titanium vs Aluminum for Aerospace and Medical Parts: How to Choose - Where Titanium Is Actually the Right Choice - Strength, Density and Specific Strength - Grade 2 or Ti-6Al-4V - What Titanium Changes on the Machine - Surface Finishes: What Works on Which - Where Buyers Over-Specify Titanium, and What It Costs - What to put on the drawing - Sources - Frequently Asked Questions - Related Articles - Not Sure Whether the Part Really Needs Titanium? Materials # Titanium vs Aluminum for Aerospace and Medical Parts: How to Choose October 28, 2026 | 8 min read ## Titanium vs Aluminum for Aerospace and Medical Parts: How to Choose Ti-6Al-4V is 4.43 g/cm³ and gives 895–930 MPa tensile; 6061-T6 is 2.70 g/cm³ and gives 310 MPa. Divide by density and the ranking changes: Ti-6Al-4V reaches 202.0–209.9 MPa per g/cm³, 7075-T6 reaches 203.6, and 6061-T6 reaches 114.8. That is the whole decision in one line — 7075-T6 aluminum carries the same load per unit of weight as Ti-6Al-4V, at 40% of the titanium material cost. So the question is never "which material is stronger". It is "does this part need titanium's strength and its corrosion or biocompatibility behaviour, or only its strength?" ## Where Titanium Is Actually the Right Choice Start from the duty, not from the material list. Titanium earns its place when the service environment does the arguing for it. | Your Situation | Use Titanium? | Better Alternative | Aerospace / airframe structural | Yes | — | Medical implants (biocompatibility) | Yes | — | Marine (saltwater, no heat) | Maybe | 316L stainless is cheaper for non-load parts | Chemical processing (corrosive) | Maybe | Hastelloy or super duplex may be better | High strength-to-weight (non-aero) | Maybe | 7075-T6 aluminum is cheaper if non-corrosive | Just need lightweight + strong | No | 7075 aluminum (same strength, 40% the cost) | Just need corrosion resistance | No | 316 stainless (5–10x cheaper) | Prototype / low volume | No | Prototype in aluminum or steel first Two "Yes" rows, three "Maybe" rows and three "No" rows. A buyer who lands on titanium has to clear one of the two "Yes" rows, or argue a "Maybe" row on engineering grounds. Everything else is paying the premium for a property the part does not use. [Ti-6Al-4V medical implant machined from titanium] Medical implants are one of the two cases where titanium is genuinely the right choice. ## Strength, Density and Specific Strength | Property | 6061-T6 | 7075-T6 | 2024-T4 | Grade 2 (CP) | Ti-6Al-4V | Tensile (MPa) | 310 | 572 | 469 | 275–410 | 895–930 | Yield (MPa) | 275 | 503 | 324 | 170–275 | 825–860 | Density (g/cm³) | 2.70 | 2.81 | 2.78 | 4.51 | 4.43 | Elongation | 12% | 11% | 20% | — | — | Hardness | 95 HB | 150 HB | 120 HB | 200–275 HB | 33–36 HRC | Machinability | Excellent | Good | Fair | Better | Hard on tools | Weldable | Yes | No | No | Yes | Difficult (requires protection) | Relative cost | 1.0x | 1.8–2.5x | 1.5–2.0x | 1.0x | 1.3–1.5x Read the hardness row carefully: Grade 2 at 200–275 HB and Ti-6Al-4V at 33–36 HRC are not on the same scale, so do not compare them directly. What matters is the contrast with aluminum — 6061-T6 at 95 HB and 7075-T6 at 150 HB are the two most machinable options on the table, and that difference is where most of the cost of titanium comes from. [Scatter chart of tensile strength against density for 6061-T6, 2024-T4, 7075-T6, Grade 2 and Ti-6Al-4V] Strength against density: the aluminum alloys sit far to the left, titanium sits high but heavy. The specific strength column is the one that settles most arguments: | Material | Tensile (MPa) | Density (g/cm³) | Specific tensile (MPa per g/cm³) | 6061-T6 | 310 | 2.70 | 114.8 | 7075-T6 | 572 | 2.81 | 203.6 | 2024-T4 | 469 | 2.78 | 168.7 | Grade 2 (CP) | 275 | 4.51 | 61.0 | Ti-6Al-4V | 895 | 4.43 | 202.0 7075-T6 and Ti-6Al-4V land within 1% of each other per unit of weight. 2024-T4 is the aluminum choice when fatigue endurance matters — 20% elongation and 469 MPa — and it is the grade used in aircraft skins and wing structures, which is why it appears in aerospace drawings next to titanium. Grade 2 at 61.0 is nowhere near either of them; its case is corrosion and biocompatibility, not strength. [Bar chart comparing specific tensile strength of 6061-T6, 2024-T4, 7075-T6, Grade 2 and Ti-6Al-4V] Specific tensile strength: 7075-T6 at 203.6 and Ti-6Al-4V at 202.0 are effectively equal. ## Grade 2 or Ti-6Al-4V | Property | Grade 2 (CP) | Ti-6Al-4V (Grade 5) | Type | Commercially pure | Alpha-beta alloy | Tensile (MPa) | 275–410 | 895–930 | Yield (MPa) | 170–275 | 825–860 | Density (g/cm³) | 4.51 | 4.43 | Hardness | 200–275 HB | 33–36 HRC | Weldable | Yes | Difficult (requires protection) | Heat treatable | No | Yes (aging increases strength) | Machinability | Better | Hard on tools | Relative cost | 1.0x | 1.3–1.5x | Use for | Chemical, marine, biomedical | Aerospace, high-strength The rule is short: corrosion resistance without high strength means Grade 2; high strength at low weight means Ti-6Al-4V. One trap worth naming — Grade 2 yield reaches only 275 MPa, which is weaker than 6061-T6. Specifying Grade 2 for a highly loaded structural part is a downgrade, not an upgrade. [Ti-6Al-4V alpha-beta titanium CNC machined impeller] Ti-6Al-4V: the alpha-beta alloy behind aerospace structure and high-strength parts. ## What Titanium Changes on the Machine Titanium is not an expensive material that you machine like aluminum. It is a different process with different rules, and the rules are what drive the cost. [Bar chart comparing roughing cutting speed ranges for 6061-T6, 7075-T6, Grade 2 and Ti-6Al-4V] Roughing speed ranges: aluminum runs 300-500 m/min, titanium 20-60 m/min. | Material | Roughing (m/min) | Finishing (m/min) | Tooling note | 6061-T6 | 300–500 | 500–800 | Aggressive, 6061 cuts easy | 7075-T6 | 200–350 | 350–550 | 20–30% slower than 6061 | Grade 2 titanium | 30–60 | — | Positive rake, sharp edge | Ti-6Al-4V | 20–45 | — | TiAlN or diamond coating, 3–5x longer life Four rules decide whether a titanium part succeeds or becomes scrap: - Low cutting speed. Grade 2 runs 30–60 m/min and Ti-6Al-4V runs 20–45 m/min. Going faster only burns the tool without cutting faster. - Flood coolant is mandatory. Titanium has poor thermal conductivity, so heat stays at the cutting edge. Without flood coolant, tool life drops to minutes. - Replace tools on first sign of wear. Titanium work-hardens. A dull tool leaves a hardened surface layer that kills the next tool as well. TiAlN or diamond-coated end mills last 3–5x longer. - Thin chips, multiple shallow passes. Keep the radial depth of cut small, because thick chips generate too much heat. And one safety rule that has no equivalent in aluminum: never use cutting oil. Fine titanium chips can ignite, and a titanium fire burns at 3000°C+ — it cannot be extinguished with water because it burns hotter. Use water-based flood coolant and keep the machine clean of chips. [Aerospace titanium CNC machined parts] Aerospace structural parts are the other place titanium earns its cost. ## Surface Finishes: What Works on Which | Treatment | Titanium | Aluminum | Anodize (Type II) | Blue, purple and gold colours; popular for medical and aerospace | 6061 gives the most consistent colour; 7075 comes out dark and uneven | Hard anodize (Type III) | — | 7075 hard coat is less wear-resistant | Grit blasting | Matte finish, required before many coating processes | Surface preparation | Polishing | Polishes well but is labour-intensive | Electropolish possible, but not common | PVD coating | TiN and CrN for reduced friction; used in medical implants | — Two practical notes. First, anodizing adds 10–25 µm per surface, so on a tight feature the part goes oversize after coating — machine undersize by half the anodize thickness before it goes out. Second, titanium anodizing is a different electrochemistry from aluminum anodizing even when both are called Type II; a supplier who has only run aluminum lines is not automatically qualified for a titanium [Anodized medical titanium implant surface detail] Medical titanium is commonly anodized Type II, which gives the blue, purple and gold colours. finish. ## Where Buyers Over-Specify Titanium, and What It Costs | Mistake | What happens | Correct approach | Specifying titanium when aluminum suffices | Paying 5–10x material cost for no benefit | Do the strength/weight/corrosion calculation. Most parts do not need titanium. | High cutting speed | Tool burns out in minutes, poor surface finish | Keep below 60 m/min for Grade 2, 45 m/min for Ti-6Al-4V | Using cutting oil | Fire risk with titanium chips | Water-based coolant only | Not changing tools frequently enough | Work-hardened surface kills subsequent tools | Replace at first sign of wear | Grade 2 for high-strength parts | Yield only 275 MPa — weaker than 6061-T6 | High strength requires Ti-6Al-4V [6061-T651 aluminum CNC machined part] 6061-T651 aluminum: the cheaper route whenever the duty does not demand titanium. The cost stack behind the first row is worth spelling out, because it is what a buyer actually pays: titanium raw material costs 5–10x more than aluminum and 3–5x more than stainless, machining costs 2–3x more than steel, and a prototype belongs in aluminum or steel first. ### What to put on the drawing 1- The grade and the condition together — Ti-6Al-4V or Grade 2, and whether it is annealed, solution treated or aged. "Titanium" alone leaves the strength open. 1- The environment — saltwater, body contact, chemical spray. If none of these apply, say so on the drawing; it is the fastest way to justify an aluminum alternative. 1- The load and its direction — if the part is not loaded past 503 MPa, 7075-T6 aluminum covers it. 1- The finish — Type II anodize, PVD or bare, fixed before the part is quoted, because anodizing changes the dimensions. 1- The prototype path — if the part is still in development, machine the first article in 6061-T6 and switch to titanium only once the design is frozen. ## Sources Every number on this page comes from our engineering wiki. - [Titanium Alloys ](https://www.sinbo-machining.com/wiki/materials/titanium/) - [Aluminum Alloys ](https://www.sinbo-machining.com/wiki/materials/aluminum/) ## Frequently Asked Questions Specify titanium only where its combination of strength, weight and corrosion resistance is genuinely required: aerospace or airframe structure, and medical implants. Otherwise the alternatives win on cost. 7075-T6 aluminum gives the same strength at 40% of the titanium cost, and 316 stainless is 5–10x cheaper when only corrosion resistance is needed. Titanium raw material costs 5–10x more than aluminum and 3–5x more than stainless, machining costs 2–3x more than steel, and a prototype belongs in aluminum or steel first. Decide on strength first, then check the environment. Grade 2 commercially pure titanium gives tensile 275–410 MPa, yield 170–275 MPa, density 4.51 g/cm³ and hardness 200–275 HB; it is weldable and kinder to tooling. Ti-6Al-4V gives tensile 895–930 MPa, yield 825–860 MPa, density 4.43 g/cm³ and 33–36 HRC, but welding it is difficult and it is hard on tools. Simple rule: corrosion resistance without high strength means Grade 2; high strength at low weight means Ti-6Al-4V. Keep the speed low and keep coolant flooding. Grade 2 runs 30–60 m/min and Ti-6Al-4V runs 20–45 m/min; going faster burns the tool without cutting faster, so stay under 60 m/min and 45 m/min respectively. Flood coolant is mandatory because titanium has poor thermal conductivity — heat stays at the cutting edge and tool life drops to minutes without it. Use positive rake tools with a sharp edge, and TiAlN or diamond-coated end mills last 3–5x longer. Never use cutting oil. Fine titanium chips can ignite, especially in dry machining, and a titanium fire burns at 3000°C+ and cannot be extinguished with water because it burns hotter — so use water-based flood coolant and keep the machine clean of chips. On the work-hardening side, replace tools frequently: a dull tool leaves a hardened surface layer that kills the next tool as well. Keep radial depth of cut small and take multiple shallow passes, because thick chips generate too much heat. ## Related Articles [6061 vs 7075 Aluminum: How to Choose for CNC Parts Read more → ](https://www.sinbo-machining.com/blog/6061-vs-7075-aluminum/)[Aluminum vs Steel for CNC Machining Read more → ](https://www.sinbo-machining.com/blog/aluminum-vs-steel/)[CNC Machining Services Read more → ](https://www.sinbo-machining.com/services/cnc-machining/)#titanium vs aluminum #Ti-6Al-4V #Grade 2 titanium #aerospace machining #medical implant #CNC material selection [Back to Blog ](https://www.sinbo-machining.com/blog/) ## Not Sure Whether the Part Really Needs Titanium? Send us the drawing and our engineers will check the load, the environment and the budget before recommending a material. [Get Quote ](https://www.sinbo-machining.com/quote/)[Contact Us ](https://www.sinbo-machining.com/contact/)