What Is the Difference Between Gr23 and Gr5 Titanium Bars?
Titanium alloys are among the most important materials in modern engineering, offering an exceptional combination of strength, light weight, and corrosion resistance. They are widely used in industries such as aerospace, medical, chemical processing, and marine engineering. Among the various titanium grades available, Grade 5 (Ti-6Al-4V) and Grade 23 (Ti-6Al-4V ELI) are two of the most commonly used.
While they share a similar chemical composition, their mechanical properties, applications, and performance characteristics differ significantly due to variations in purity and interstitial element content.
In this article, we’ll examine in detail the difference between Gr23 and Gr5 titanium bars, their unique properties, and how sakyalloy, a leading supplier of high-performance titanium alloys, ensures top-quality production for global industries.
Overview of Titanium Grades
Titanium is classified into multiple grades based on alloying elements and purity levels. Among these, Gr5 (Ti-6Al-4V) and Gr23 (Ti-6Al-4V ELI) both belong to the alpha-beta titanium alloy family, which means they contain both alpha and beta crystal phases — offering an excellent balance of strength and formability.
However, the main difference lies in the ELI designation in Grade 23, which stands for Extra Low Interstitials. This refinement in chemistry gives Gr23 unique advantages in critical applications that demand enhanced toughness, ductility, and biocompatibility.
Chemical Composition Comparison
| Element | Gr5 (Ti-6Al-4V) | Gr23 (Ti-6Al-4V ELI) |
|---|---|---|
| Aluminum (Al) | 5.5–6.75% | 5.5–6.5% |
| Vanadium (V) | 3.5–4.5% | 3.5–4.5% |
| Iron (Fe) | ≤0.40% | ≤0.25% |
| Oxygen (O) | ≤0.20% | ≤0.13% |
| Nitrogen (N) | ≤0.05% | ≤0.05% |
| Carbon (C) | ≤0.08% | ≤0.08% |
| Hydrogen (H) | ≤0.015% | ≤0.012% |
| Titanium (Ti) | Balance | Balance |
Key Difference:
Grade 23 has lower levels of interstitial impurities — oxygen, nitrogen, and iron — which significantly improves its toughness, fracture resistance, and ductility.
Mechanical Properties Comparison
| Property | Gr5 Titanium Bar | Gr23 Titanium Bar |
|---|---|---|
| Density | 4.43 g/cm³ | 4.43 g/cm³ |
| Tensile Strength (MPa) | 895 | 860 |
| Yield Strength (MPa) | 828 | 795 |
| Elongation (%) | 10 | 14 |
| Hardness (HRC) | 36 | 34 |
| Fracture Toughness | Moderate | High |
Interpretation:
-
Grade 5 is stronger and harder, ideal for high-stress mechanical applications.
-
Grade 23 offers better ductility and fracture toughness, suitable for impact-sensitive or fatigue-critical applications such as implants or aircraft structures.
Microstructural Differences
The microstructure of both alloys consists of alpha and beta phases; however, the lower oxygen and iron content in Grade 23 results in:
-
Cleaner microstructure with fewer inclusions.
-
Improved uniformity during cold working and forming.
-
Enhanced fatigue strength and resistance to crack initiation.
This refined structure makes Grade 23 the preferred choice for precision-machined components and load-bearing medical implants.
Corrosion Resistance
Both Gr5 and Gr23 offer excellent corrosion resistance in various environments, including seawater, acid, and saline body fluids.
| Environment | Gr5 | Gr23 |
|---|---|---|
| Seawater | Excellent | Excellent |
| Acidic Media | Good | Good |
| Chloride Solutions | Excellent | Excellent |
| Biological Fluids | Very Good | Outstanding |
Why Gr23 Performs Better in Biomedical Use:
The reduced interstitials minimize micro-galvanic reactions and improve passive oxide layer stability, ensuring superior corrosion resistance inside the human body or medical devices.
Processing and Machinability
Both grades are weldable and machinable with proper techniques, but Gr23’s lower oxygen content improves formability and reduces the risk of microcracking during forming or deep drawing.
| Process | Gr5 | Gr23 |
|---|---|---|
| Machining | Fair (requires high-speed tools) | Easier due to higher ductility |
| Welding | Excellent (in inert atmosphere) | Excellent (less embrittlement) |
| Forming | Moderate | Superior |
| Polishing | Good | Excellent surface finish achievable |
For high-precision parts such as orthopedic implants or turbine fasteners, Gr23 provides a smoother machining performance and superior polishability.
Applications of Gr5 Titanium Bar
Gr5 (Ti-6Al-4V) is the most widely used titanium alloy globally, often referred to as the “workhorse” of the titanium family. Its high strength-to-weight ratio makes it indispensable for:
-
Aerospace components: Landing gear parts, fasteners, and compressor blades.
-
Automotive performance parts: Engine valves, connecting rods, and exhaust systems.
-
Industrial equipment: Heat exchangers, pressure vessels, and chemical processing components.
-
Marine structures: Propeller shafts, offshore risers, and underwater fasteners.
It is the go-to material where mechanical strength takes priority over extreme ductility.
Applications of Gr23 Titanium Bar
Gr23 (Ti-6Al-4V ELI) was specifically developed for applications requiring biocompatibility and superior fracture toughness.
-
Medical implants: Orthopedic screws, dental implants, bone plates, and spinal fixation systems.
-
Aerospace: Structural parts that require fatigue resistance, such as fasteners and thin-walled components.
-
Cryogenic and deep-sea equipment: Components exposed to extreme temperatures or pressures.
-
Chemical processing: High-purity reaction vessels and fittings.
The ELI (Extra Low Interstitial) composition ensures improved fatigue life, making it suitable for applications where failure could be catastrophic.
Comparative Summary
| Property / Application | Gr5 Titanium Bar | Gr23 Titanium Bar |
|---|---|---|
| Composition | Ti-6Al-4V | Ti-6Al-4V ELI (Extra Low Interstitials) |
| Strength | Higher | Slightly Lower |
| Ductility | Good | Superior |
| Fracture Toughness | Moderate | Excellent |
| Biocompatibility | Good | Outstanding |
| Fatigue Resistance | High | Very High |
| Cost | Lower | Slightly Higher |
| Primary Applications | Aerospace, Marine, Industrial | Medical, Aerospace, Cryogenic |
Key Takeaway:
Choose Gr5 for mechanical strength and engineering performance, and Gr23 for critical applications requiring superior toughness and purity, especially in medical or aerospace fields.
Standards and Specifications
Both grades comply with international standards, ensuring consistency and quality in manufacturing and performance.
| Standard | Description |
|---|---|
| ASTM B348 | Titanium and titanium alloy bars and billets |
| AMS 4928 | Aerospace material specification for Ti-6Al-4V |
| ASTM F136 | Implant-grade titanium alloy (Gr23) |
| ISO 5832-3 | Medical implant specification (Gr23 ELI) |
At sakyalloy, both Gr5 and Gr23 titanium bars are manufactured strictly according to these standards, ensuring traceability, reliability, and consistent mechanical properties for every batch.
Quality Control at sakyalloy
sakyalloy is a professional manufacturer and exporter of titanium and specialty alloy bars, dedicated to providing high-purity, precision-machined products for global industries.
Manufacturing Highlights:
-
Raw materials sourced from certified titanium sponge suppliers.
-
Precision melting via vacuum arc remelting (VAR) for purity control.
-
Controlled forging, rolling, and heat treatment to ensure uniform grain structure.
-
Ultrasonic, eddy current, and tensile testing to verify defect-free performance.
-
Full Mill Test Certificates (MTC) with chemical and mechanical data.
With advanced production lines and strict quality assurance, sakyalloy guarantees both Gr5 and Gr23 titanium bars meet international aerospace and medical standards.
Why Choose sakyalloy
-
Global Expertise: Decades of experience supplying titanium alloys for aerospace, defense, and medical industries.
-
Comprehensive Product Range: Gr1 to Gr23 titanium bars, sheets, tubes, and custom machined parts.
-
Customization: Tailored dimensions, surface finishes, and tolerance control.
-
Certified Quality: ISO 9001, ISO 13485, and ASTM/AMS compliance.
-
Technical Support: Expert engineers providing guidance on alloy selection and fabrication processes.
With sakyalloy, you’re not just choosing a supplier — you’re partnering with a team dedicated to delivering precision, reliability, and innovation in every titanium component.
Conclusion
Although Gr5 and Gr23 titanium bars share a similar chemical foundation (Ti-6Al-4V), their differences in purity and interstitial control give them distinct advantages in different industries.
-
Gr5 Titanium Bar: Ideal for aerospace, marine, and industrial applications where strength and performance are the top priorities.
-
Gr23 Titanium Bar: Perfect for medical and high-purity applications where fracture toughness, ductility, and biocompatibility are essential.
By offering both alloys with the highest quality assurance, sakyalloy ensures customers receive materials that meet stringent international standards and perform reliably under the most demanding conditions.
Whether you’re designing aircraft components or life-saving implants, understanding the difference between Gr5 and Gr23 titanium bars is key to choosing the right material for long-term success.