Differences Between Grade 5 and Grade 2 Titanium Alloys

Grade 2 and Grade 5 are the two most widely used titanium alloys, but they differ significantly in composition, mechanical properties, performance, and applications.

Grade 2 titanium is commercially pure titanium with no major alloying elements, while Grade 5, also known as Ti‑6Al‑4V, is an alpha‑beta alloy containing 6% aluminum and 4% vanadium. This chemical difference directly determines their performance.

 

Grade 5 has much higher strength. Its tensile strength is approximately 860–1050 MPa, far stronger than Grade 2's 340–450 MPa. Grade 5 also has better fatigue resistance and creep resistance at elevated temperatures, making it suitable for high‑stress structural components. By contrast, Grade 2 is softer, more ductile, and easier to form, bend, and weld.

However, Grade 2 pure titanium has slightly better general corrosion resistance, especially in reducing acids and highly corrosive environments. Grade 5 offers good corrosion resistance but may be slightly affected by certain aggressive media.

Grade 2 is easier to machine, fabricate, and deep draw, so it is widely used in sheet metal parts. Grade 5 is stronger and harder, requiring more powerful equipment for processing, and its machining is more difficult.

 

Grade 2 cannot be significantly strengthened by heat treatment. Grade 5 can be annealed, solution treated, and aged to further improve strength and hardness.

Grade 2 is mainly used in components requiring excellent corrosion resistance and moderate strength, such as heat exchangers, pipes, valves, marine parts, chemical equipment, and architectural applications. Grade 5 is used in high‑performance fields including aerospace, aviation engines, medical implants, military components, high‑strength fasteners, and racing parts.

Grade 2 is chosen for good corrosion resistance, ductility, and ease of fabrication, while Grade 5 is selected for high strength, fatigue resistance, and high‑performance structural applications.