Titanium Grade 2 vs Grade 5

Pure corrosion resistance.
Or alloyed strength.
Very different uses.

Titanium Grade 2 is commercially pure — best corrosion resistance, lower strength. Titanium Grade 5 (Ti-6Al-4V) is the aerospace workhorse alloy — much higher strength, less corrosion resistance. The right choice depends on whether your application is corrosion-driven or strength-driven.

Get a Quote DFM guide

01 · At a glance

Side-by-side summary.

Option A

Titanium Gr.2 (CP)

Commercially pure titanium. Unalloyed, most corrosion-resistant grade. Lower strength (275 MPa yield) but excellent formability. For chemical, marine, and low-load corrosion-critical applications.

Option B

Titanium Gr.5 (Ti-6Al-4V)

Aerospace workhorse. 6% Al + 4% V alloyed for strength. Triple the yield strength of Gr.2 (828 MPa). Standard for aerospace structural, medical implants (prototype), racing components.

02 · Detailed comparison

Feature-by-feature breakdown.

Attribute	Gr.2 (CP)	Gr.5 (Ti-6Al-4V)
Yield strength	275 MPa	828 MPa
Tensile strength	345 MPa	895 MPa
Density	4.51 g/cc	4.43 g/cc
Elongation	20%	10%
Hardness	165 HB	334 HB
Corrosion resistance	Excellent (best titanium grade)	Very good (slightly less than Gr.2)
Seawater service	Excellent	Good
Machinability	Difficult (gummy, galling)	Difficult (work hardening)
Weldability	Excellent	Good (requires care)
Formability	Excellent (can be cold-worked)	Limited (must be hot-formed)
Heat treatable	No	Yes (alpha-beta alloy)
Cost (per kg)	$30–50	$50–80
Typical use	Chemical, marine, low-load	Aerospace, implants, structural
AMS spec	AMS 4902	AMS 4928

03 · Decision guide

When to choose each.

Choose Titanium Gr.2 (CP) when:

Seawater heat exchangers
Chemical processing (especially chlorides)
Desalination plant equipment
Low-load corrosion-critical applications
Formed parts (cold-worked sheet metal)
Welded pressure-vessel applications

Choose Titanium Gr.5 (Ti-6Al-4V) when:

Aerospace structural brackets and components
Medical implants (Gr.23 ELI preferred for permanent implants)
Racing and motorsport components
High-strength fasteners and bolts
Suspension and structural hardware
Any application where strength-to-weight ratio matters

FAQ

Common questions.

Corrosion resistance. Gr.2 resists hot HCl, seawater, chloride environments, and many aggressive chemicals where Gr.5 may suffer from localized corrosion due to alloying element segregation. For chemical processing, desalination, marine heat exchangers — Gr.2 is the right choice. Gr.5's strength is wasted in these applications where loads are typically low but corrosion environment is severe.

Sometimes — depends on specific corrosion environment. Gr.5 matches or exceeds 316L stainless for many corrosion applications, with much higher strength and lower weight. However, 316L is far cheaper and Gr.5 machining is more expensive. Choose Gr.5 when: weight matters (aerospace, racing) + corrosion resistance needed. Choose 316L when: general corrosion resistance needed and cost matters.

Multiple factors: low thermal conductivity (heat concentrates at tool), high strength at temperature (tool pressure remains high), reactive with carbide tools at elevated temperature (chemical wear), galling tendency. Result: titanium machining uses slow cutting speed (30–50 m/min vs 150 for steel), flood coolant, carbide or CBN tooling. Machining time is typically 3–4× equivalent steel. This drives much of titanium part cost premium.

Gr.23 (Ti-6Al-4V ELI, Extra Low Interstitial) is preferred for permanent implants — lower iron, oxygen, and carbon content provides better fracture toughness and ductility. Gr.5 is used for temporary fixtures, dental implants, surgical instruments. For orthopedic implants, spine cages, joint components: specify Gr.23. Material cost is similar; the compositional difference matters for long-term implant performance.

Titanium at welding temperature (above 600 °C) aggressively absorbs oxygen, nitrogen, and hydrogen from air — causing embrittlement. Weld must be shielded by argon on both sides during welding AND cooling until below 300 °C. Visual color check: straw color OK, blue indicates mild contamination, purple/grey indicates severe contamination requiring grinding and re-welding. Our titanium welding station has glove-box purge capability for critical applications.

Ti-6Al-4V is heat-treatable via solution treatment + aging. Standard temper: solution anneal at 900–950 °C + water quench + age at 480–540 °C. Achieves 925 MPa yield (up from 828 MPa annealed). Cost premium of 15–25% vs annealed material. For aerospace structural, heat-treated Gr.5 is standard. For prototypes and general mechanical, mill-annealed Gr.5 is usually adequate.