You’ve completed your initial research and determined that titanium is the ideal metal for your next project. Congratulations – this is an important first step. However, selecting the specific titanium grade is equally crucial for your project’s success.
With multiple grades of commercially pure titanium and numerous titanium alloys available, understanding their differences ensures you choose the optimal material for your specific requirements.
While all titanium grades share excellent corrosion resistance, impressive strength-to-weight ratios, and lightweight properties, significant differences exist that can dramatically impact your project’s outcome. This comprehensive guide will help you navigate these differences and select the perfect titanium grade for your application.
Key Factors in Titanium Grade Selection
Before diving into specific grades, consider these critical factors that should guide your selection process:
- Application Requirements: What function will the titanium component serve?
- Environmental Conditions: Will the material face extreme temperatures, corrosive chemicals, or saltwater exposure?
- Part Size and Complexity: Does your design require extensive forming or welding?
- Mechanical Demands: What strength, ductility, and toughness does your application require?
- Budget Constraints: How does cost factor into your material selection?
Commercially Pure Titanium Grades (Unalloyed Titanium)
Commercially pure (CP) titanium—Grades 1 to 4—contains minimal impurities and no alloying elements. Strength increases with grade number, while formability decreases. They are defined by ASTM B265 as unalloyed titanium with varying interstitial content.
Grade 1 Titanium: The Most Formable Pure Grade
As the softest CP titanium grade (per ASTM B265-02), Grade 1 offers exceptional ductility, impact toughness, and weldability—making it ideal for applications requiring complex forming or tight tolerances. Its low strength is offset by its ability to be shaped into thin sheets, tubes, or intricate parts.
- Core Traits: High formability, excellent weldability, low tensile strength (minimum 240 MPa), superior corrosion resistance in mild environments.
- Common Product Forms: Plates, tubing, piping, sheets, strips.
- Typical Applications: Aerospace frames, medical device casings, marine piping, desalination components, architectural accents.
Grade 2 Titanium: The Versatile, Cost-Effective Choice
Grade 2 is the most widely used titanium grade—thanks to its balanced strength (higher than Grade 1) and formability, plus broad availability that lowers costs. It retains Grade 1’s corrosion resistance while adding enough tensile strength (minimum 345 MPa) for more demanding roles.
- Core Traits: Balanced formability/weldability, moderate tensile strength, cost-efficient, compatible with most fabrication processes.
- Common Product Forms: Bars, billets, plates, wires, seamless tubing.
- Typical Applications: Power generation components, hydrocarbon processing equipment, exhaust pipe shrouds, airframe skin, heat exchangers.
Grade 3 Titanium: Strength Meets Corrosion Resistance
Less common than Grade 2 but valuable for harsh environments, Grade 3 offers higher strength (minimum 450 MPa) than lower CP grades while maintaining good weldability and extreme corrosion resistance. Its reduced formability is a tradeoff for enhanced durability.
- Core Traits: Higher strength than Grades 1-2, excellent corrosion resistance, moderate weldability, limited formability.
- Common Product Forms: Bars, billets, ingots, plates, welded products.
- Typical Applications: Chemical processing tanks, marine hardware, aerospace structural parts, offshore oil/gas components.
Grade 4 Titanium: The Strongest Pure Titanium
Grade 4 is the strongest CP titanium grade (minimum 550 MPa tensile strength) per ASTM standards, with good cold formability and reliable weldability. Its strength and durability make it a staple in high-stress industrial and medical applications, even as formability is its lowest among CP grades.
- Core Traits: Highest strength in CP titanium, good cold forming, excellent weldability, durable in harsh conditions.
- Common Product Forms: Bars, billets, ingots, plates, strips.
- Typical Applications: Surgical hardware (screws, plates), heat exchangers, CIP (Clean-in-Place) equipment, industrial valves.
Titanium Alloys: Enhanced Performance for Specialized Needs
Titanium alloys combine titanium with elements like aluminum, vanadium, palladium, or molybdenum to boost specific properties—such as high-temperature resistance, corrosion resistance, or biocompatibility. They outperform CP titanium in extreme or specialized scenarios.
Grade 5 (Ti 6Al-4V): The “Workhorse” Titanium Alloy
Grade 5 (Ti 6Al-4V) is the most widely used titanium alloy globally, defined by ASTM B265 as a titanium-aluminum-vanadium blend. It earns its “aerospace workhorse” title by withstanding temperatures up to 600°F (315°C) while delivering exceptional strength-to-weight ratio.
- Core Traits: High tensile strength (minimum 860 MPa), heat resistance up to 600°F, excellent corrosion resistance, highly formable.
- Common Product Forms: Bars, billets, foil, sheets, seamless pipe, wire, plates.
- Typical Applications: Aircraft turbines, aerospace structural components, high-performance engine parts, sports equipment (golf clubs, bike frames), biomedical implants.
Grade 7 Titanium: The Most Corrosion-Resistant Alloy
Grade 7 is a CP titanium variant with 0.12-0.25% palladium added (per ASTM B265), making it the most corrosion-resistant titanium grade. It retains Grade 2’s formability and weldability while excelling in aggressive chemical environments.
- Core Traits: Superior corrosion resistance (even in acids), good formability/weldability, similar baseline properties to Grade 2.
- Common Product Forms: Plates, sheets, tubing, bars—most standard product forms.
- Typical Applications: Chemical production equipment, pharmaceutical processing tanks, acid handling systems, offshore corrosion-resistant parts.
Grade 12 Titanium: The Fabrication-Friendly Alloy
Grade 12 (Ti 0.3Mo-0.8Ni) matches the strength of 300-series stainless steel while offering far better corrosion resistance. Its high formability and weldability make it ideal for custom-fabricated parts, per ASTM B265 specifications.
- Core Traits: Stainless steel-like strength, excellent formability/weldability, high corrosion resistance.
- Common Product Forms: Bars, billets, plates, strips, wire, welded pipe/tubing.
- Typical Applications: Heat exchangers, chemical manufacturing vessels, marine components, aerospace fabricated parts.
Grade 23 (Ti 6Al-4V ELI): Biocompatible & High-Strength
Grade 23 (Ti 6Al-4V ELI) is an “Extra Low Interstitial” variant of Grade 5, with reduced impurities for enhanced biocompatibility. It offers high tensile/yield strength while maintaining sufficient durability for medical and high-performance applications.
- Core Traits: Exceptional biocompatibility, high tensile strength (minimum 860 MPa), reduced ductility vs. Grade 5, corrosion resistance.
- Common Product Forms: Coils, strands, wires, flat wires, seamless pipe/tubing.
Extended Titanium Alloy Range
Beyond the commonly used grades discussed above, titanium alloys extend up to Grade 38, each with specialized characteristics tailored for specific applications. These specialized alloys offer unique combinations of properties for highly specific requirements.
Titanium Grade Selection Checklist
Use this practical checklist to guide your titanium grade selection:
- Identify Primary Requirement: Is it formability, strength, corrosion resistance, or high-temperature performance?
- Assess Environmental Factors: Consider chemical exposure, temperature extremes, and potential corrosion sources
- Evaluate Manufacturing Needs: Determine welding, forming, and machining requirements
- Review Regulatory Requirements: Ensure compliance with industry-specific standards
- Analyze Total Cost: Consider both material costs and manufacturing expenses
Frequently Asked Questions
Q: What’s the main difference between pure titanium and titanium alloys?
A: Pure titanium offers excellent corrosion resistance and formability, while titanium alloys provide enhanced strength, specialized properties, and improved performance under specific conditions.
Q: Which titanium grade is most cost-effective?
A: Grade 2 titanium typically offers the best balance of performance and cost for general applications due to its wide availability.
Q: What’s the best titanium grade for medical implants?
A: Grade 23 is specifically designed for medical applications, offering excellent biocompatibility and mechanical properties suitable for implants.
Q: Which titanium grade handles high temperatures best?
A: Grade 5 titanium maintains its properties at temperatures up to 600°F, while specialized high-temperature alloys are available for more extreme conditions.
Conclusion: Making Your Final Selection
Choosing the right titanium grade requires careful consideration of your specific application requirements, environmental conditions, and performance expectations. By understanding the unique properties of each grade and how they align with your project needs, you can select the optimal material that ensures performance, durability, and cost-effectiveness.
Remember that while this guide covers the most common titanium grades, consulting with material specialists can provide valuable insights for specialized applications. The right titanium grade selection will deliver the perfect balance of properties to make your project successful.
Other Titanium Alloys
Though the most common titanium alloys were listed above, there are many other, less known and used titanium alloys. Titanium alloys go all the way up to grade 38, and their characteristics and applications vary based on the alloy metals.
When determining what grade of titanium or titanium alloy that would be right for your project, consider the environment it will be in, what the part will do, and the size of the desired part.
If you have additional questions or you’re ready to make your titanium or titanium alloy order, contact Titanium Processing Center today.