Titanium alloy grades may vary due to different manufacturing standards and countries. Here are some common titanium alloy grades and their equivalents in different countries/regions:

ASTM Standard (United States):

Ti-6Al-4V (Grade 5): ASTM B348, ASTM F136, AMS 4928 Ti-3Al-2.5V (Grade 9): ASTM B265, ASTM B348, AMS 4943 Ti-6Al-4V ELI (Grade 23): ASTM F136, ASTM B348, AMS 4931 ISO Standard (International):

Ti-6Al-4V: ISO 5832-3 Ti-3Al-2.5V: ISO 5832-11 Ti-6Al-4V ELI: ISO 5832-13 EN Standard (Europe):

Ti-6Al-4V: EN 3497, EN 3516 Ti-3Al-2.5V: EN 3691, EN 3692 Ti-6Al-4V ELI: EN 3496 GB Standard (China):

TC4 (Ti-6Al-4V): GB/T 3620.1, GB/T 13810 TC11 (Ti-3Al-2.5V): GB/T 13810 TC20 (Ti-6Al-4V ELI): GB/T 13810 JIS Standard (Japan):

Ti-6Al-4V: JIS H 4600 Ti-3Al-2.5V: JIS H 4601 Ti-6Al-4V ELI: JIS H 4604 It's important to note that different countries and industries may have different nomenclatures for the same alloy grade, and certain standards may have different versions. When selecting titanium alloys, it's advisable to refer to specific standard documents to ensure that the products meet particular quality and performance requirements