Titanium Grades Explained: CP Titanium & Alloys

Introduction

Titanium is used in chemical processing, marine equipment, power generation, medical devices, aerospace components and many other demanding applications. Its combination of corrosion resistance, relatively low density and useful mechanical properties makes it an important engineering material. However, titanium is not a single material with one fixed set of properties. Different grades have different chemical compositions, strength levels, formability, corrosion performance and product-standard requirements.

The first step in selecting a titanium material is to understand the difference between commercially pure (CP) titanium and titanium alloys. CP grades are often selected for corrosion resistance, formability and fabrication. Alloy grades are used when higher strength, fatigue performance or application-specific properties are required.

This guide introduces commonly specified grades, explains how their characteristics differ and outlines what buyers should verify before ordering. It is a general material-selection guide, not a substitute for the applicable material specification, engineering assessment or regulatory approval.

For closer comparisons, see our related guides to Grade 1 vs Grade 2 Titanium, Grade 5 Titanium and Grade 23 Titanium.

1. Understanding Titanium Grade Systems

Titanium grades are designations used by standards and material specifications to identify materials with defined chemistry and, where applicable, mechanical and product requirements. A grade name alone does not describe every requirement for a supplied product.

Common designations encountered in international purchasing include:

ASTM Grade designations, such as Grade 2, Grade 5 and Grade 23.
UNS numbers, which provide a material identification system used alongside specifications. For example, Grade 2 is commonly identified as UNS R50400 and Ti-6Al-4V Grade 5 as UNS R56400. Always check the relevant specification for the exact designation.
Chinese GB/T designations, such as TA2, TC4 and TA18.
Russian GOST designations, such as BT1-0 and VT6.

These systems are not interchangeable code lists. Similar names or alloy families do not prove that two materials have identical chemical limits, mechanical properties, manufacturing routes or inspection requirements.

Commercially pure titanium and titanium alloys

Commercially pure titanium contains titanium with controlled levels of residual elements and impurities; it is not necessarily 100% chemically pure. In the commonly used ASTM grade system, Grades 1–4 are the conventional CP grades. Their strength generally increases from Grade 1 to Grade 4, while formability and ductility generally decrease.

Titanium alloys contain intentional alloying additions such as aluminium, vanadium, molybdenum or nickel. These additions modify properties such as strength, hardenability, creep resistance or corrosion behaviour. Grade 5 (Ti-6Al-4V), Grade 9 (Ti-3Al-2.5V) and Grade 12 (Ti-0.3Mo-0.8Ni) are examples of alloy grades.

Some grades need separate explanation. Grade 7 is palladium-modified unalloyed titanium and is commonly grouped with modified CP grades. Grade 23 is the extra-low-interstitial version of Ti-6Al-4V, commonly referred to as Ti-6Al-4V ELI.

What does ELI mean?

ELI stands for Extra Low Interstitials. In Ti-6Al-4V ELI, the limits for certain interstitial elements are controlled more tightly than in standard Ti-6Al-4V. These controls are relevant to properties such as ductility and fracture toughness. ELI is a specification-related material condition, not simply a marketing label. Buyers should identify the required grade and applicable specification, especially for medical or other regulated applications.

2. Commercially Pure (CP) Titanium Grades

ASTM Grades 1–4 are widely used commercially pure titanium grades. Their differences are important when balancing strength, forming operations, fabrication requirements and service conditions.

Grade 1 Titanium

Grade 1 is the lowest-strength and generally most ductile of the conventional CP grades. Its high formability makes it useful for applications involving substantial forming or fabrication. It is selected in some chemical-processing, heat-exchanger, marine and architectural applications where corrosion resistance and formability are important.

Typical selection considerations:

Very good formability among conventional CP grades.
Lower strength than Grades 2, 3 and 4.
Often considered for deep drawing, forming and components with demanding fabrication requirements.
Final suitability depends on the actual environment, product condition and design requirements.

Grade 1 should not automatically be chosen simply because it has the highest nominal purity among the CP grades. The required strength, product form, fabrication route and service environment must also be considered.

Grade 2 Titanium

Grade 2 is one of the most widely specified CP titanium grades because it offers a practical balance of corrosion resistance, strength, weldability and formability. It is commonly used in chemical-processing equipment, piping systems, heat exchangers, condensers, marine components and general industrial fabrication.

Typical selection considerations:

Moderate strength compared with the other conventional CP grades.
Good general-purpose formability and weldability when appropriate procedures are used.
Broad use in industrial equipment exposed to suitable corrosive environments.
Often considered where Grade 1's lower strength is insufficient but an alloy grade is unnecessary.

Grade 2 is not universally suitable for every chemical environment. Corrosion performance depends on the chemical species, concentration, temperature, flow conditions, crevices, contamination and other operating factors.

Grade 3 Titanium

Grade 3 provides higher strength than Grades 1 and 2, while retaining useful corrosion resistance and fabrication characteristics. It may be considered when a CP titanium material is required but Grade 2 does not provide sufficient strength.

It is less commonly encountered than Grade 2 in many general purchasing channels. Availability, product form, dimensions and delivery condition should therefore be confirmed at the enquiry stage. Do not assume that a Grade 3 product can be substituted with Grade 2 based only on a similar application description.

Grade 4 Titanium

Grade 4 is the highest-strength conventional CP titanium grade. It is used when the design requires more strength than Grades 1–3 can provide while retaining the characteristics associated with unalloyed titanium.

Its higher strength is accompanied by lower formability than the lower-numbered CP grades. Forming, machining and welding plans should be assessed against the supplied product condition and component geometry. Grade 4 may be considered for selected chemical, marine, aerospace-related and industrial applications, subject to the applicable specification and design review.

Comparing Grades 1–4

| Grade | General strength level within CP Grades 1–4 | Relative formability | Common selection focus | |---|---|---|---| | Grade 1 | Lowest | Highest | Formability and corrosion resistance | | Grade 2 | Moderate | Good | General-purpose industrial balance | | Grade 3 | Higher than Grades 1–2 | Lower than Grades 1–2 | Additional strength within CP titanium | | Grade 4 | Highest | Lowest among Grades 1–4 | Higher strength within CP titanium |

This is a qualitative guide, not a table of guaranteed mechanical values. Actual minimum properties and permitted ranges depend on the product form, thickness or diameter, delivery condition and governing specification.

3. Common Titanium Alloy Grades

Titanium alloys are selected when the requirements extend beyond those typically met by CP titanium. Their properties depend on alloy chemistry, microstructure, processing route, heat treatment and product form.

Grade 5 Titanium (Ti-6Al-4V)

Grade 5, commonly known as Ti-6Al-4V, is an alpha-beta titanium alloy containing aluminium and vanadium as principal alloying elements. It is one of the most widely used titanium alloys because of its high strength-to-weight ratio and broad engineering use.

Applications include aerospace structures and components, high-performance industrial equipment, selected marine components, automotive engineering and other weight-sensitive applications. Its use in a particular component depends on design allowables, fatigue requirements, operating temperature, manufacturing route and the governing specification.

Selection considerations:

Significantly higher strength than conventional CP titanium grades.
Good strength-to-weight characteristics.
Available in multiple product forms, subject to specification and supplier capability.
More demanding forming and machining considerations than many CP grades.
Welding and heat-treatment requirements need to be controlled by qualified procedures.

Fatigue performance is not represented by one universal value. It is affected by material condition and microstructure, surface finish, residual stress, processing history, component geometry, defects and the applied load spectrum. Design work should use fatigue data appropriate to the actual product form, manufacturing condition and service environment rather than a generic value from a grade summary.

For a deeper discussion, see Grade 5 Titanium (Ti-6Al-4V): Properties and Industrial Applications.

Grade 23 Titanium (Ti-6Al-4V ELI)

Grade 23 is the extra-low-interstitial version of Ti-6Al-4V. It retains the same principal alloying system as Grade 5 but has tighter limits for interstitial elements under the applicable material specification. These controls are important in applications where ductility, fracture toughness and consistency are critical.

Grade 23 is widely associated with medical and surgical implant applications, but the term "Grade 23" alone does not establish that a material is approved for a particular medical device or implant. Buyers and manufacturers must confirm the exact specification, product form, processing history, traceability, testing and regulatory requirements for the intended use.

ASTM F136 covers wrought Ti-6Al-4V ELI alloy for surgical implant applications. It has a different scope from ASTM B265, which covers titanium and titanium alloy strip, sheet and plate. A material meeting a general product specification should not automatically be described as meeting an implant specification.

For further detail, see Grade 23 Titanium (Ti-6Al-4V ELI): Properties and Medical Applications.

Grade 9 Titanium (Ti-3Al-2.5V)

Grade 9 is a titanium alloy containing approximately 3% aluminium and 2.5% vanadium by nominal alloy designation. It is often selected for tubing and other applications requiring a balance of strength, weight and formability. It can provide higher strength than CP titanium while remaining more formable than some higher-strength titanium alloys.

Grade 9 is used in selected aerospace, sporting, hydraulic and industrial tubing applications. Its suitability depends on product form, manufacturing condition, pressure or fatigue design requirements and the applicable product specification. Do not assume that tubing requirements apply to plate, bar or other forms.

Grade 12 Titanium (Ti-0.3Mo-0.8Ni)

Grade 12 is a corrosion-resistant titanium alloy containing molybdenum and nickel. It is used in selected chemical-processing environments where its corrosion resistance may offer advantages over commercially pure titanium.

Its suitability must be evaluated against the actual chemical composition, concentration, temperature and operating conditions. It should not be treated as a universal substitute for Grade 7 or any other titanium grade. Corrosion data for a specific medium should be reviewed before material selection.

Grade 7 Titanium (Palladium-Modified Unalloyed Titanium)

Grade 7 is a palladium-modified unalloyed titanium grade. It is commonly grouped with modified commercially pure titanium grades, but should be distinguished from conventional CP Grades 1–4. The palladium addition can improve corrosion resistance in certain reducing-acid environments.

Grade 7 is considered for selected chemical-processing equipment and components exposed to environments where its enhanced corrosion behaviour is beneficial. It is not a universal solution for all acids or process conditions. Concentration, temperature, impurities, aeration, velocity and crevice conditions can materially affect performance. Obtain corrosion data for the actual process environment before specifying the grade.

4. Common Titanium Grades Comparison

The following table is a high-level screening guide. It is not a substitute for the chemistry and mechanical-property limits in the relevant specification.

| Grade | Material family / designation | General characteristics | Typical application areas | |---|---|---|---| | Grade 1 | CP titanium | Lowest strength and highest formability among CP Grades 1–4 | Formed chemical equipment, heat exchangers, selected marine applications | | Grade 2 | CP titanium | General-purpose balance of strength, formability and corrosion resistance | Chemical processing, piping, condensers, industrial fabrication | | Grade 3 | CP titanium | Higher strength than Grades 1–2 | Selected industrial components requiring additional CP strength | | Grade 4 | CP titanium | Highest strength among conventional CP Grades 1–4 | Selected industrial and engineered components | | Grade 5 | Ti-6Al-4V | High strength-to-weight ratio; alpha-beta alloy | Aerospace, high-performance industrial and weight-sensitive components | | Grade 7 | Palladium-modified unalloyed titanium | Improved corrosion resistance in certain reducing-acid environments | Selected chemical-processing equipment | | Grade 9 | Ti-3Al-2.5V | Strength and formability balance; frequently used for tubing | Aerospace and industrial tubing, selected lightweight structures | | Grade 12 | Ti-0.3Mo-0.8Ni | Alloyed titanium for selected corrosion-service environments | Chemical-processing equipment | | Grade 23 | Ti-6Al-4V ELI | Extra-low-interstitial Ti-6Al-4V; specification-controlled | Medical and surgical implant material, subject to applicable requirements |

How to interpret this comparison

"Typical application" does not mean automatic suitability. The actual service environment and engineering design govern.
The same grade may have different permitted properties across product standards and product forms.
A grade designation does not by itself establish compliance with a particular ASTM, GB/T, GOST or medical-device specification.
Where a project has a defined specification, do not substitute a similar grade without documented technical approval.

5. Titanium Grade Cross-Reference: Chinese, American and Russian Standards

The following table provides a preliminary cross-reference of common titanium grade designations used in the United States (ASTM), China (GB/T) and Russia (GOST 19807-91). It is intended as a starting point for international material identification and purchasing discussions.

| Material type | USA (ASTM) | China (GB/T) | Russia (GOST 19807-91) | |---|---|---|---| | Commercially pure titanium | Grade 1 | TA1 | BT1-00 / BT1-0 (related CP titanium grades; not a direct one-to-one match) | | Commercially pure titanium | Grade 2 | TA2 | BT1-00 / BT1-0 (related CP titanium grades; verify chemistry before comparison) | | Commercially pure titanium | Grade 3 | TA3 | No direct equivalent confirmed | | Commercially pure titanium | Grade 4 | TA4 | No direct equivalent confirmed | | Ti-6Al-4V | Grade 5 | TC4 | VT6 (similar alloy family; not automatically equivalent) | | Palladium-modified titanium | Grade 7 | TA9 | No direct equivalent confirmed | | Ti-3Al-2.5V | Grade 9 | TA18 | No direct equivalent confirmed | | Ti-0.3Mo-0.8Ni | Grade 12 | TA10 | No direct equivalent confirmed | | Ti-6Al-4V ELI | Grade 23 | TC4 ELI* | No direct equivalent confirmed |

Important note: The designations in this table provide a preliminary cross-reference for international material identification and purchasing discussions. They do not establish automatic equivalence between national standards. Even when two grades belong to a similar material family, their chemical composition limits, impurity requirements, mechanical properties, delivery conditions and inspection requirements may differ.

Russian designations such as BT1-00, BT1-0 and VT6 should be treated as related or comparable material designations rather than direct substitutes for ASTM grades. The exact grade mapping must be checked against the relevant national standard and product specification.

The Russian BT1-00 and BT1-0 designations are shown only as related commercially pure titanium grades. Neither designation should be assigned as a direct equivalent to a specific ASTM CP grade without a full comparison of chemical composition and applicable product requirements.

TC4 ELI is a commonly used Chinese designation for an extra-low-interstitial Ti-6Al-4V material. Buyers should verify the applicable GB/T or product-specific specification and chemical requirements before treating it as equivalent to ASTM Grade 23.

Before purchasing or substituting titanium materials, buyers should verify the applicable standard, complete chemical composition, mechanical properties, product form, delivery condition and inspection documentation. For regulated applications, confirm any additional qualification, traceability and regulatory requirements.

6. How to Choose the Right Titanium Grade

Selecting a titanium grade should begin with the service requirements, not with the grade name alone. The following sequence can help organize a material enquiry.

1. Define the operating environment

Identify the process medium and relevant operating conditions, including:

Chemical composition and concentration.
Operating and cleaning temperatures.
Flow velocity, aeration and possible erosion.
Crevices, deposits, galvanic contact and contamination.
Expected service life and maintenance conditions.

For corrosion-critical applications, consult corrosion data for the actual environment and seek specialist review where necessary. General statements such as "titanium is corrosion resistant" are not enough to approve a material for a specific process.

2. Establish the mechanical requirements

Determine the design loads and the required strength, stiffness, fatigue resistance, fracture toughness and temperature capability. Use the mechanical-property requirements from the applicable specification for the exact product form and delivery condition.

Do not select a grade from tensile strength alone. Fatigue, fracture behaviour, welds, forming operations, stress concentrations and manufacturing defects may be equally important.

3. Consider fabrication and processing

Review the planned manufacturing route:

Will the material need deep drawing, bending, rolling or other forming?
Will it be welded, machined, forged or assembled?
Are there restrictions on heat input, surface contamination or post-weld treatment?
Does the finished component require special dimensional tolerances or surface condition?

A grade that performs well in service may still be unsuitable for a particular manufacturing route without additional process development.

4. Confirm product form and governing standard

Specify whether the requirement is for plate, sheet, strip, foil, bar, billet, forging, tube, wire, fitting or a finished machined component. Then identify the standard applicable to that product form and the required edition or contractual revision.

For example, ASTM B265 addresses titanium and titanium alloy strip, sheet and plate; ASTM B348/B348M addresses bars and billets. These standards have different scopes. Neither should be treated as a universal specification for every titanium product form.

5. Check documentation and end-use requirements

A purchase specification may need to define:

Grade and applicable material standard.
Product form, dimensions and tolerances.
Delivery condition and heat-treatment condition, where applicable.
Chemical composition and mechanical testing requirements.
Inspection, test reports, marking and traceability.
Packaging, preservation and destination requirements.
Any additional industry, customer or regulatory qualification.

For medical, aerospace, pressure equipment or other regulated applications, the material specification is only one part of the qualification process. Confirm the complete requirements with the design authority and applicable regulatory framework.

7. Titanium Product Forms and Material Specifications

Titanium grades are supplied in different product forms, and the governing standards are not necessarily the same for each form. A buyer should identify both the grade and the product form when requesting a quotation.

Common product forms include:

Plate and sheet: Used in tanks, vessels, heat exchangers, cladding and fabricated equipment. ASTM B265 is a relevant specification for titanium and titanium alloy strip, sheet and plate.
Strip and coil: Used where continuous or cut-to-length material is required. Confirm the applicable strip requirements, thickness, width, coil dimensions and surface condition.
Bars and billets: Used for machining, forging stock and engineered components. ASTM B348/B348M covers titanium and titanium alloy bars and billets.
Forgings: Used for components requiring a forged product form and defined mechanical properties. Specify the applicable forging standard, grade, dimensions, heat treatment and testing requirements.
Tubes and pipes: Used in heat exchangers, piping and fluid-handling systems. Confirm whether seamless or welded construction is required, along with the applicable tube or pipe specification.
Wire and fasteners: Require product-specific dimensional, mechanical, surface and testing requirements.
Machined and fabricated components: Require a clear drawing, material specification, tolerances, surface requirements, inspection plan and acceptance criteria.

A standard applicable to one product form should not be applied automatically to another. For example, ASTM B265 should not be cited as the governing standard for titanium bar, tube, wire or forgings.

8. Chinese, American and Russian Standards: What Buyers Should Verify

International buyers may encounter different grade names on drawings, mill certificates, quotations and legacy equipment documentation. A cross-reference table is useful for initial identification, but it is not sufficient for technical approval.

Before accepting an alternative designation, compare:

Chemical composition: Check every specified element and impurity limit, not just the principal alloying elements.
Mechanical properties: Compare the required tensile, yield, elongation and other specified values for the relevant product form and thickness or diameter.
Product form and condition: Confirm whether the material is plate, bar, tube, forging or another form, and whether the delivery and heat-treatment conditions match.
Testing and inspection: Check sampling, test methods, frequency, acceptance criteria and documentation.
Contractual and regulatory requirements: Confirm which standard and edition govern the order and whether the end user permits substitutions.

The following standards are relevant to some of the grades and product forms discussed in this guide. Their scopes are different, so the buyer must select the standard that matches the actual product and application.

| Standard | General scope relevant to this guide | Important limitation | |---|---|---| | GB/T 3620.1 | Designations and chemical composition of titanium and titanium alloys | Does not by itself define every product-form mechanical or delivery requirement | | ASTM B265 / B265M | Titanium and titanium alloy strip, sheet and plate | Not a bar, billet, tube, wire or forging specification | | ASTM B348 / B348M | Titanium and titanium alloy bars and billets | Not a strip, sheet, plate, tube, wire or implant-specific specification | | ASTM F67 | Unalloyed titanium for surgical implant applications | Applies to unalloyed titanium, not Ti-6Al-4V alloys | | ASTM F136 / F136M | Wrought Ti-6Al-4V ELI alloy for surgical implant applications | Specific to the stated alloy and implant application scope | | GOST 19807-91 | Wrought titanium and titanium alloys; grade designations | Confirm current applicability, product requirements and acceptance in the destination market |

Standards are revised periodically. Always check the current edition, amendments and contractual requirements with the standards publisher or the responsible standards authority before placing an order.

9. Frequently Asked Questions

What is the difference between CP titanium and titanium alloys?

CP titanium grades are unalloyed titanium grades with controlled residual and impurity levels. Conventional ASTM CP Grades 1–4 differ mainly in strength and formability. Titanium alloys contain intentional alloying additions that modify properties. Grade 5, for example, contains aluminium and vanadium and offers much higher strength than CP titanium.

Is Grade 5 titanium the same as Ti-6Al-4V?

Grade 5 is the commonly used ASTM grade designation for Ti-6Al-4V. However, the grade name alone does not define every requirement. Confirm the applicable product specification, product form, delivery condition and testing requirements.

What does ELI stand for in Grade 23 titanium?

ELI means Extra Low Interstitials. Grade 23 is Ti-6Al-4V ELI, with tighter limits for certain interstitial elements than standard Grade 5 under the applicable specification. The exact requirements should be checked against the governing standard.

Which titanium grade is best for medical implants?

There is no single best grade for every implant. ASTM F67 covers unalloyed titanium for surgical implant applications, while ASTM F136 covers wrought Ti-6Al-4V ELI alloy for surgical implant applications. The correct material depends on the device design, applicable standards, regulatory requirements and qualification process. A grade designation alone does not establish approval for a medical device.

Which titanium grade is easiest to form and weld?

Among conventional CP Grades 1–4, Grade 1 generally offers the highest formability, followed by Grades 2, 3 and 4. Actual forming and welding performance depends on thickness, product condition, joint design, cleanliness, equipment and qualified procedures. Alloy grades may require different and more tightly controlled processing practices.

Can Chinese and American titanium grades be used as direct substitutes?

Not automatically. Some Chinese and ASTM designations refer to similar material families, but chemistry limits, mechanical requirements, product standards and inspection rules may differ. Compare the full specifications and obtain technical approval before substitution.

Does ASTM B265 apply to all titanium products?

No. ASTM B265 / B265M covers titanium and titanium alloy strip, sheet and plate. Other product forms, such as bars and billets, have separate specifications, including ASTM B348 / B348M. Tubes, forgings, wire and finished components also require their own applicable requirements.

10. Conclusion

Titanium grade selection is a balance of corrosion performance, strength, formability, fabrication requirements, product form and applicable standards. Conventional CP Grades 1–4 cover a range from high formability to higher strength. Alloy grades such as Grades 5, 9 and 12 provide different combinations of mechanical and corrosion properties, while Grade 7 and Grade 23 have specific characteristics that require careful interpretation.

For international purchasing, grade cross-reference tables should be treated as screening tools rather than proof of equivalence. The full material specification, product form, delivery condition, testing and end-use requirements must be confirmed before ordering or substitution.

Discuss Your Titanium Material Requirements

Feinuotai supports titanium material enquiries covering grade identification, product-form selection, dimensions, applicable specifications and quantity requirements. Depending on the product and project, supply may involve available material stock, coordinated sourcing, machining, fabrication or customized processing through our supplier network. Not all manufacturing steps are performed in Feinuotai-owned facilities.

To help assess an enquiry, provide the following information where available:

Required grade or material designation.
Applicable standard and revision.
Product form and dimensions.
Quantity and delivery destination.
Intended application and any special testing or documentation requirements.
Drawing or technical specification, if a customized component is required.

Contact our team to discuss your titanium material requirements and the appropriate supply or processing route.

References and Further Reading

The following standards are relevant to the material designations and product forms discussed in this article. Consult the official publisher or standards authority for the current edition and full requirements.

GB/T 3620.1-2016 — Designation and composition requirements for titanium and titanium alloys. Check the current edition in the Chinese National Standards database.
ASTM B265 / B265M — Standard Specification for Titanium and Titanium Alloy Strip, Sheet, and Plate.
ASTM B348 / B348M — Standard Specification for Titanium and Titanium Alloy Bars and Billets.
ASTM F67 — Standard Specification for Unalloyed Titanium, for Surgical Implant Applications.
ASTM F136 / F136M — Standard Specification for Wrought Titanium-6Aluminum-4Vanadium ELI (Extra Low Interstitial) Alloy for Surgical Implant Applications.
GOST 19807-91 — Wrought Titanium and Titanium Alloys. Grades. Verify current status and applicability for the destination market and contract.

Official standards resources:

GB/T 3620.1-2016: https://std.samr.gov.cn/ (Chinese National Standards database – search by standard number)
ASTM B265 / B265M: https://store.astm.org/standards/b265
ASTM B348 / B348M: https://store.astm.org/standards/b348
ASTM F67: https://store.astm.org/standards/f67
ASTM F136 / F136M: https://store.astm.org/standards/f136
GOST 19807-91: https://protect.gost.ru/ (Russian Federal Information Fund of Standards – search by designation)

Editorial note: This article is a general educational overview. It does not replace the full text of a material standard, corrosion assessment, engineering design review or regulatory approval. Confirm the exact grade, product form, specification, delivery condition and documentation requirements for each order.

Titanium Grades Explained: A Guide to Commercially Pure Titanium and Titanium Alloys