Short answer
| Aspect | Grade 2 | Grade 5 (Ti-6Al-4V) |
|---|---|---|
| Tensile strength, min | 345 MPa | 895 MPa |
| Yield strength, min | 275 MPa | 828 MPa |
| Elongation, min | 20% | 10% |
| Alloying | None — unalloyed CP titanium | 6% aluminium, 4% vanadium |
| Heat treatment | Annealed only | Annealed or solution treated and aged |
| Formability | Better | Harder, particularly cold forming |
| Machinability | Better | Slower, more tool wear |
| Weldability | Excellent | Good, with more care |
| Corrosion in oxidising media | Comparable | Comparable |
| Relative cost | Lower — the baseline for comparison | Higher per kilo and higher per finished part |
Composition
| Element | Grade 2 (ASTM) | Grade 5 (ASTM) |
|---|---|---|
| Aluminium | — | 5.50 – 6.75 |
| Vanadium | — | 3.50 – 4.50 |
| Iron, max | 0.30 | 0.40 |
| Oxygen, max | 0.25 | 0.20 |
| Carbon, max | 0.08 | 0.08 |
| Nitrogen, max | 0.03 | 0.05 |
| Hydrogen, max | 0.015 | 0.015 |
| Titanium | Balance | Balance |
Published composition requirements of the referenced ASTM specifications. Grade mill test reports report the actual analysis of the heat supplied.
Mechanical properties
| Property | Grade 2 | Grade 5 | Difference |
|---|---|---|---|
| Tensile strength | 345 MPa | 895 MPa | Grade 5 is about 2.6× |
| Yield strength | 275 MPa | 828 MPa | Grade 5 is about 3.0× |
| Elongation | 20% | 10% | Grade 2 has twice the ductility |
| Typical density | 4.51 g/cm³ | 4.43 g/cm³ | Grade 5 is slightly lighter |
| Typical modulus | approx. 105 GPa | approx. 114 GPa | Grade 5 is slightly stiffer |
Strength values are specification minimums; density and modulus are typical reference figures. Solution-treated and aged Grade 5 exceeds the annealed minimums shown here.
Strength-to-weight, stated properly
The headline reason for choosing Grade 5 is often quoted as strength-to-weight. It is real, and it is also worth being precise about: compared on specific strength, Grade 5 offers roughly twice the strength for about 2% less density. That is why a Grade 5 bracket can be lighter than a Grade 2 one carrying the same load.
The gain matters when mass is the design constraint — aerospace, motorsport, moving parts. It does not matter for a static vessel shell, a pipe run or a tank, where the section size is set by fabrication and handling rather than by allowable stress.
Workability: forming versus machining
| Operation | Grade 2 | Grade 5 |
|---|---|---|
| Cold bending and drawing | Readily formed; generous bend radii | Limited cold formability; may need warm forming |
| Machining | Cuts reasonably with sharp tools and good chip control | Cuts slower, generates more heat, higher tool wear and cost |
| Welding | Forgiving, excellent joint efficiency | Weldable but requires stricter control; joints do not reach aged parent strength |
| Heat treatment needed | No — annealed is the supply condition | Only when STA properties are required |
The practical consequence: a Grade 5 part costs more than its material premium suggests, because machining time and tool cost rise too. Where a part is heavily machined, that difference often dominates the quotation.
Scenario picks
- Seawater piping, cooling water, desalination → Grade 2. Corrosion performance is equivalent and Grade 2 costs less and forms better.
- Chemical vessel shell, column, tank → Grade 2. Strength is rarely governing and the fabrication savings are real.
- CNC machined structural components → Grade 5, if the load case genuinely requires it; otherwise Grade 2 machines faster and cheaper.
- Motorsport and aerospace-adjacent hardware → Grade 5, where mass saved justifies both material and machining cost.
- Fasteners under real preload → Grade 5 is common here; check the strength your joint actually needs before specifying it.
- Welded assemblies → Grade 2 unless strength dictates otherwise; it welds more forgivingly.
The common mistake
The single most common specification error we see is Grade 5 being specified because the application sounds demanding, without a strength calculation behind it. The buyer pays substantially more per kilo, pays again in machining, gains nothing in corrosion resistance, and sometimes loses ductility and weldability that the fabrication actually needed.
The discipline that avoids it: specify Grade 5 when a load case requires it, and say explicitly why you are doing so in the enquiry. If that sentence is difficult to write, Grade 2 is probably right.
Full detail on each grade
Grade 2 titanium
Composition, properties, forms and typical uses.
Grade 2 page →
Grade 5 / Ti-6Al-4V
Composition, annealed versus STA, size ranges.
Grade 5 page →
Undecided? Quote both. Send the same specification twice and the difference in price will tell you most of what you need.
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Send the form, dimensions and quantity and we will quote Grade 2 and Grade 5 side by side, with the lead-time implication of each. It costs nothing to see the difference before deciding.
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