Titanium Grade Selection Guide
Titanium Grade Selection Guide
An Engineering Decision Framework for Selecting the Right Titanium Grade
Selecting the correct titanium grade is an engineering decision, not a catalog choice.
This guide provides a step-by-step framework to help engineers, EPCs, and technical buyers choose the appropriate titanium grade based on operating environment, corrosion risk, mechanical requirements, and lifecycle objectives.
Step 1. Define the Operating Environment
Begin by clearly identifying the service conditions:
Medium: seawater, brine, cooling water, chemical fluids
Chloride level: low / moderate / high
Temperature: ambient / elevated
Flow condition: continuous / intermittent / stagnant
Service duration: short-term / long-term / decades
If corrosion resistance governs the design, start with commercially pure titanium, not alloys.
Step 2. Identify the Dominant Failure Mechanisms
Determine which risks control material performance:
General corrosion
Pitting or crevice corrosion
Stress corrosion cracking
Mechanical load or fatigue
Fabrication or welding sensitivity
Understanding the dominant failure mode is essential before selecting any grade.
Step 3. Select the Baseline Material (Default Choice)
Titanium Grade 2 – Baseline Selection
Choose Grade 2 when:
Seawater or cooling water service is present
Flow conditions are well controlled
Crevice risk is limited
Long-term corrosion resistance is required
Grade 2 is the default starting point for most industrial, marine, power, and desalination applications.
Step 4. Evaluate the Need for Corrosion Margin Upgrade
Upgrade from Grade 2 only when specific risks are identified.
Upgrade to Grade 16 (Risk-Balanced Choice)
Select Grade 16 when:
Corrosion risk exists but is moderate
Flow is generally good but not guaranteed
Limited crevice conditions are present
Cost control is important
Grade 16 provides enhanced corrosion resistance at controlled cost.
Upgrade to Grade 7 (Severe Corrosion Conditions)
Select Grade 7 when:
Low-flow or stagnant conditions exist
Crevice-prone geometries cannot be avoided
Reducing environments are present
Failure consequences are unacceptable
Grade 7 offers the highest corrosion margin among CP titanium grades.
Step 5. Assess Mechanical and Structural Requirements
If mechanical strength or fatigue governs the design, corrosion resistance may not be the primary driver.
Titanium Grade 5 (Ti-6Al-4V)
Select Grade 5 when:
High strength-to-weight ratio is required
Structural load or fatigue dominates
Corrosion exposure is controlled
Do NOT select Grade 5 for seawater heat exchangers, condensers, or corrosion-driven systems.
Step 6. Match Grade to Product Form and Fabrication
Confirm that the selected grade aligns with:
Product form (tubes, pipes, plates, bars, forgings)
Fabrication method (forming, welding, machining)
Inspection and testing requirements
CP and Pd-alloyed titanium grades generally offer superior weldability and formability compared with titanium alloys.
Step 7. Verify Standards and Project Requirements
Ensure compliance with applicable specifications:
ASTM / ASME material standards
Project-specific requirements
Third-party inspection (if required)
Certification level (EN 10204 3.1 / 3.2)
Material selection is incomplete without standards verification.
Quick Reference: Titanium Grade Selection Matrix
Common Selection Mistakes to Avoid
Choosing Grade 5 for corrosion resistance
Upgrading to Grade 7 without identified risk
Ignoring flow and crevice design
Selecting grade before defining service conditions
Correct selection balances performance, risk, and cost.
How This Guide Connects to Other Sections
Overview – engineering context and material philosophy
Grades & Materials – detailed grade behavior
Applications – environment-specific guidance
Products – manufacturable forms
Standards & Quality – compliance and inspection
This guide acts as the decision hub for the entire titanium knowledge base.