Titanium vs Aluminum Weight: Density, Strength-to-Weight and Cost
At the same volume, common titanium grades weigh about 1.6 to 1.7 times as much as common aluminum alloys. Aluminum is therefore roughly 37% to 40% lighter at identical dimensions. Titanium can still win after a real redesign if higher strength, corrosion resistance, temperature capability or a tighter package allows a much smaller part.
Aluminum wins a same-size weight test. The winner for a working part depends on what limits the design.
If the drawing stays unchanged, use density and choose aluminum for lower mass. If geometry can change, compare each material against the same load, deflection, fatigue life, temperature, corrosion environment, manufacturing route and cost target. That is the only fair same-function comparison.
Ti-6Al-4V is about 63% heavier than 6061 and about 58% heavier than 7075 for the same solid volume.
Grade 5 titanium can offset its density when a much smaller load-carrying section is allowed and validated.
Specific modulus is similar. Deep aluminum profiles, ribs and hollow sections can be very mass-efficient.
Include stock yield, machining, tooling, special processes, inspection, logistics and service life—not price per kilogram alone.
From density to a purchase decision
Compare 6061 and 7075 aluminum with Grade 2 and Grade 5 titanium.
“Titanium” and “aluminum” are not purchase specifications. Density changes slightly by alloy, while strength can change greatly with grade, temper, product form, thickness and direction. The values below are useful for early screening; final design must use the governing specification or approved allowables.
| Material example | Density | Equal-volume result | Representative strength basis | Strong first use |
|---|---|---|---|---|
| 6061-T6 / T651 aluminum | ≈2.70–2.71 g/cm³ ≈0.098 lb/in³ | Lightest example; reference = 1.00× | Kaiser typical sheet/plate: 276 MPa yield, 310 MPa UTS | Welded frames, extrusions, plates, housings and general machinery |
| 7075-T6 / T651 aluminum | ≈2.80 g/cm³ ≈0.101 lb/in³ | ≈1.03× 6061; still much lighter than titanium | Kaiser typical sheet/plate: 503 MPa yield, 572 MPa UTS | High-specific-strength machined parts where welding is not required |
| Titanium Grade 2 | ≈4.51–4.52 g/cm³ ≈0.163 lb/in³ | ≈1.66× 6061 by volume | ATI minimum: 275 MPa yield, 345 MPa UTS | Corrosion-led marine, chemical-process, vessel and heat-exchanger service |
| Ti-6Al-4V Grade 5 | ≈4.42 g/cm³ ≈0.160 lb/in³ | ≈1.63× 6061; ≈1.58× 7075 | TIMET ASTM B265 annealed sheet/plate minimum: 828 MPa yield, 895 MPa UTS | Compact, highly loaded, hot or envelope-constrained components |
The strength rows use a mix of published typical values and product-specific minimums. They show scale, not a common design-allowable basis. Compare the same product form, thickness, direction, condition, temperature and statistical basis before sizing a part.
“Same size” and “same function” are two different comparisons.
| Comparison | What stays constant | Best first metric | Likely starting conclusion |
|---|---|---|---|
| Identical dimensions | Solid volume and geometry | Density, ρ | Aluminum is about 37–40% lighter. |
| Axial strength-limited member | Load, length and allowable basis | Allowable strength ÷ density | Grade 5 titanium may offset density with a smaller area. |
| Axial stiffness-limited member | Load, length and allowed extension | Young’s modulus ÷ density | Common aluminum and titanium alloys are broadly similar per mass. |
| Beam or panel in bending | Span, load, support and deflection | E × section moment I | Profile depth, ribs and packaging may matter more than material name. |
| Buckling-limited structure | Length, end conditions and stability margin | E × I or shell model | Higher strength does not permit automatic proportional thinning. |
| Finished component | All performance, production and service needs | Validated mass + total cost | Either material can win after redesign and testing. |
Buyer shortcut: If the drawing is frozen, compare density. If the design is open, ask each supplier for its proposed grade, condition, geometry, finished mass, purchased stock, process route, exclusions and total delivered price against the same functional requirements.
One liter of titanium weighs much more than one liter of aluminum.
Density is mass per unit volume. For any solid shape, mass = density × material volume. Hollow parts need the net metal volume, not the outside envelope volume.
≈0.098 lb per cubic inch
≈0.101 lb per cubic inch
≈0.160 lb per cubic inch
≈0.163 lb per cubic inch
Worked example: a 100 × 100 × 10 mm plate
The volume is 100,000 mm³, or 100 cm³. That gives about 271 g for 6061, 280 g for 7075, 442 g for Ti-6Al-4V and 451 g for Grade 2 titanium.
A same-size Ti-6Al-4V plate is therefore about 171 g heavier than the 6061 plate. This says nothing about whether either plate is strong or stiff enough; it only compares material volume.
Why the percentages look different: “Ti-6Al-4V is 63.1% heavier than 6061” uses aluminum as the reference. “6061 is 38.7% lighter than Ti-6Al-4V” uses titanium as the reference. Reverse percentages must be recalculated.
Compare titanium and aluminum weight for the same material volume.
Choose one aluminum alloy, one titanium grade and the solid material volume. The calculator uses the nominal densities shown in this guide. It is for quoting and early screening, not certified mass control.
For a rectangular metric plate: volume in cm³ = length × width × thickness in mm ÷ 1,000.
For 100 cm³, 6061 is about 271 g and Ti-6Al-4V is about 442 g.
Grade 5 titanium clearly outruns 6061—but 7075 closes much of the gap.
Specific strength means a chosen strength divided by density. It helps screen a strength-limited part, but the chosen value must be named. Yield strength, ultimate tensile strength, fatigue strength and a formal design allowable are not interchangeable.
Using the published example values below, ordinary 6061 is far behind Ti-6Al-4V. High-strength 7075 is much closer because it combines a low density with high room-temperature strength. Titanium may still be better when compact section size, corrosion, fatigue, temperature or bearing performance matters.
Do not use this as design data. The examples mix typical values with a product-specific minimum. Real sizing needs compatible certified values or approved allowables for the exact form, thickness, direction and service conditions.
Illustrative yield ÷ density index
Index = cited yield strength in MPa ÷ density in g/cm³. 6061, 7075 and Grade 2 use cited typical values; Ti-6Al-4V uses a TIMET ASTM B265 annealed sheet/plate minimum.
Titanium has a higher Young’s modulus, but stiffness per mass is broadly similar.
Young’s modulus controls elastic strain. Ti-6Al-4V is roughly 107–122 GPa, while 6061 and 7075 are roughly 68–71 GPa. An equal-size titanium member is therefore stiffer. But titanium is also denser, so the specific modulus E/ρ overlaps common aluminum alloys.
Axial member
k = EA / LIf load, length and permitted extension are fixed, E/ρ is the right first mass screen. Similar values mean titanium does not automatically produce a lighter tie or rod.
- 6061: ≈25.2 GPa/(g/cm³)
- 7075: ≈25.4
- Grade 2: ≈23.3–26.6
- Grade 5: ≈24.2–27.6
Beam or panel
Bending rigidity = EIFor a rectangle, I = bh³/12. Increasing section depth raises bending stiffness with the cube of depth. Low-density aluminum can use a deeper ribbed or hollow section at the same mass.
- Deep profiles can beat a compact solid plate
- Packaging may limit usable depth
- Buckling must be checked separately
- Joints and supports can control deflection
Choose a strong first candidate—then verify what could change the answer.
This selector turns the comparison into a starting route. It does not replace structural analysis, corrosion testing, material specifications or supplier confirmation.
Choose the closest case. The recommendation updates instantly.
6061 or another suitable aluminum alloy
With fixed geometry, aluminum’s lower density gives the lowest mass. 6061 is a practical general fabrication baseline.
Verify before release:- Exact alloy density and product form
- Voids, inserts, coatings and tolerances
- Whether the existing part is actually adequate
The grade should match the job—not the reputation of the material family.
6061-T6 / T651 aluminum
Start here for economical frames, profiles, housings, plates and welded machinery. It combines low density, broad availability, extrusion flexibility, good atmospheric corrosion resistance and useful thermal conductivity.
- Density
- ≈2.70–2.71 g/cm³
- Best advantage
- Fabrication + cost
- Main limit
- Lower strength; weld-zone softening
7075-T6 / T651 aluminum
Use it for high-specific-strength machined and mechanically fastened parts when room-temperature strength and low mass matter. Control corrosion, orientation, temper and short-transverse behavior.
- Density
- ≈2.80 g/cm³
- Best advantage
- Room-temperature specific strength
- Main limit
- Fusion welding and SCC sensitivity
Commercially pure Grade 2
Choose Grade 2 for qualified marine and chemical-process service, formability and weldability—not for maximum specific strength. It may reduce corrosion allowance, coating maintenance or replacement downtime.
- Density
- ≈4.51–4.52 g/cm³
- Best advantage
- Corrosion-led lifecycle value
- Main limit
- Mass and moderate strength
Ti-6Al-4V Grade 5
Use it for compact, highly loaded, fatigue-sensitive, hotter or corrosion-critical parts when its performance can reduce section size. Tight control of machining, welding cleanliness and galling is required.
- Density
- ≈4.42 g/cm³
- Best advantage
- High absolute and specific strength
- Main limit
- Stock and conversion cost
Temperature, corrosion, heat flow, joining and machining can reverse a simple ranking.
- Corrosion: titanium performs very well in many services, but no alloy is universal. Confirm fluid chemistry, temperature, flow, crevices and contaminants.
- Temperature: selected titanium grades retain useful strength above common aluminum service ranges, but use time-temperature allowables for the exact product.
- Heat spreading: aluminum is usually the better heat-sink starting point. Hydro lists about 167 W/m·K for 6061-T6 extrusion; TIMET lists about 6.6 W/m·K for Ti-6Al-4V.
- Joining: 6061 is widely weldable but loses T6 strength in the heat-affected zone. Conventional structural fusion welding is usually a poor route for 7075.
- Manufacturing: aluminum’s machining, extrusion, forming, welding and finishing ecosystem normally lowers total cost. Titanium needs tighter cutting and welding control.
- Interfaces: titanium in wet contact with aluminum can drive galvanic attack of the aluminum. Design isolation, sealing and drainage together.
Price per kilogram is only the first layer of finished-part cost.
Titanium normally costs more as comparable stock and usually costs more again after conversion. There is no reliable permanent multiplier. Grade, form, specification, dimensions, quantity, origin, certification, stock yield, process time and lead time all change the result.
Mill stock
Exact grade, condition, form, certification and minimum order.
Purchased envelope
Billet, plate or forging size; trim, saw and facing allowance.
Conversion
Machining time, tools, coolant, forming, welding and fixtures.
Special processes
Heat treatment, coating, cleaning, peening or passivation.
Quality & delivery
Traceability, NDT, CMM, first article, packaging and freight.
Lifecycle
Inspection, coating renewal, downtime, replacement and residual value.
Use material yield and buy-to-fly ratio
Material yield = finished mass ÷ purchased mass. Buy-to-fly ratio is the inverse: purchased mass ÷ finished mass. A 1 kg part machined from 4 kg of stock has 25% material yield and a buy-to-fly ratio of 4.
Titanium scrap may have value, but scrap credit does not repay machine hours, cutting tools, inspection or the risk of rejecting a nearly finished part. Near-net forgings, castings, additive preforms and tailored stock can reduce waste when the volume supports them.
Do not divide two commodity headlines. USGS upstream aluminum ingot and titanium sponge data describe different commodities and markets. They are not a valid price ratio for 6061 plate and Ti-6Al-4V bar. Use supplier quotes for the same form, specification, quantity, delivery term and validity date.
Hold function constant, optimize each material, then compare mass and cost.
Define the job
Record load cases, life, deflection, vibration, buckling, impact, temperature, corrosion, interfaces, volume and cost target.
Find what governs
Identify whether yield, fatigue, fracture, bearing, stiffness, buckling, heat flow, corrosion, wear or manufacturing sets the design.
Name exact candidates
Choose alloy, temper or condition, product form, thickness range and governing specification. Avoid family-level comparisons.
Redesign each option
Check stress, deflection, stability, joints, fatigue, temperature, corrosion, minimum wall and available process routes.
Calculate total mass and cost
Include hardware, inserts, coatings, purchased stock, process time, tools, inspection, certification, logistics and lifecycle.
Prototype and freeze
Validate critical functions, then release the material, process, inspection plan, substitutions and change controls.
Give suppliers enough information to compare the same job.
Technical package
- Exact candidate alloy/grade and condition
- ASTM, AMS, EN, ASME, aerospace, medical or customer specification
- Product form and finished drawing/CAD
- Permitted redesign envelope and interfaces
- Loads, life, deflection, vibration, temperature and environment
- Special processes and acceptance criteria
Quotation return
- Finished mass and center of gravity
- Purchased stock size and mass
- Material yield or buy-to-fly ratio
- Manufacturing route and cycle-time basis
- Traceability, inspection and testing included
- Total delivered unit price, lead time, exclusions and quote validity
Useful request: “Quote both materials against the same functional requirements. State the exact grade, condition, form, proposed geometry, finished weight, purchased stock, material yield, process route, lead time, exclusions and total delivered unit price.”
Avoid conclusions that sound simple but lead to a bad material choice.
Property mistakes
- Saying titanium is lighter than aluminum
- Comparing unnamed metals instead of exact grades
- Ignoring aluminum temper or titanium condition
- Mixing typical data, minimums and allowables
- Using ultimate strength when stiffness or fatigue governs
Design and buying mistakes
- Assuming stronger always means proportionally thinner
- Ignoring buckling, joints and minimum wall
- Comparing stock price per kilogram only
- Using an undated universal cost multiplier
- Forgetting galvanic isolation in wet assemblies
Related Oceanplayer engineering guides
Short answers to common titanium vs aluminum weight questions
Open a question for the practical answer. Values are nominal screening data unless a specification is named.
Is titanium lighter than aluminum?
No. Common titanium grades are about 4.42–4.52 g/cm³, while common aluminum alloys are about 2.70–2.81 g/cm³. Titanium weighs about 1.6–1.7 times as much at equal volume.
How much heavier is titanium than aluminum?
Ti-6Al-4V is about 63% heavier than 6061 and about 58% heavier than 7075 at the same volume. Grade 2 titanium is about 66% heavier than 6061.
How much lighter is aluminum than titanium?
6061 is about 39% lighter than Ti-6Al-4V at equal volume; 7075 is about 37% lighter. The percentage differs from “titanium is heavier” because the reference mass changes.
Why use titanium if aluminum is lighter?
Titanium can provide higher absolute strength, corrosion resistance, useful higher-temperature performance and a compact load path. Those benefits can justify higher mass per volume and higher cost.
Which has the better strength-to-weight ratio?
Ti-6Al-4V has a large advantage over ordinary 6061. High-strength 7075 can be much closer. The answer depends on exact grade, temper, form, thickness, direction, temperature and the strength basis used.
Is titanium stiffer than aluminum?
An equal-size titanium member is stiffer because titanium has a higher Young’s modulus. But titanium is denser, so modulus per density is broadly similar. At equal mass, section geometry often decides deflection.
Can a titanium part weigh less than an aluminum part?
Yes, after redesign, if titanium allows enough reduction in area, thickness or part count without violating stiffness, buckling, fatigue, joints, damage tolerance or manufacturing rules. A direct same-geometry swap is always heavier in titanium.
How much does one cubic inch weigh?
6061 is about 0.098 lb/in³, 7075 about 0.101 lb/in³, Ti-6Al-4V about 0.160 lb/in³ and Grade 2 titanium about 0.163 lb/in³. Multiply by the net solid volume in cubic inches.
Is titanium always more expensive than aluminum?
Titanium is normally more expensive as comparable stock and as a finished part, but no fixed ratio is reliable. Grade, form, specification, quantity, material yield, processing, certification, lead time and market conditions determine the difference.
Which is better for aerospace parts?
Neither is universally better. Aluminum commonly wins in large low-density, stiffness-driven structures. Titanium is attractive for compact highly loaded parts, hotter areas, corrosion-critical interfaces and tight envelopes. Approved aerospace allowables and certification govern the final choice.
Primary sources behind the comparison
- TIMET — TIMETAL 6-4 technical data sheet: density, modulus, thermal conductivity and product-specific minimum tensile data.
- TIMET — TIMETAL 50A technical data sheet: Grade 2 identity, density, modulus, typical strength and industrial applications.
- ATI — CP Grade 2 titanium: density, minimum tensile/yield values, product forms and specifications.
- Hydro — Alloy 6061 data sheet: density, section-dependent extrusion minimums, joining, corrosion and thermal conductivity.
- Kaiser Aluminum — 6061 sheet, coil and plate: typical room-temperature mechanical properties and process characteristics.
- Kaiser Aluminum — 7075 sheet, coil and plate: density, typical mechanical data and corrosion/process comparisons.
- ASTM B265-25 and ASTM B209/B209M: scope and grade/form framework for titanium and aluminum sheet and plate.
- U.S. Geological Survey — Mineral Commodity Summaries 2026: dated upstream aluminum and titanium market context, not finished-stock quotations.
Engineering limitation: This article is a screening and procurement guide. It does not replace certified material data, code calculations, aerospace or pressure-vessel allowables, corrosion testing, fatigue analysis, weld qualification, regulatory review or component validation.
Compare finished weight and process risk—not just the metal name.
Share the exact grade or permitted alternatives, condition, product form, drawing, redesign envelope, quantity, load and environment summary, inspection needs and delivery location. Oceanplayer can review the joining and laser-process side of the manufacturing route.