Grade 5, also known as Ti6Al4V, Ti-6Al-4V, Ti 6-4 or R56400 is the most commonly used titanium alloy. It has a chemical composition of 6% aluminium, 4% vanadium, 0.25% (maximum) iron, 0.2% (maximum) oxygen, and the remainder titanium. Grade 5 is used extensively in Aerospace, Medical, Marine, and Chemical Processing. It is significantly stronger than commercially pure titanium while having the same stiffness and thermal properties. Among its many advantages, it is heat treatable. This grade has an excellent combination of strength, corrosion resistance, weld and fabricability. In consequence, its uses are numerous such as for military aircraft or turbines. It is also used in surgical implants. Generally, it is used in applications up to 400 degrees Celsius. Its properties are very similar to those of the 300 stainless steel series, especially 316. Ti-6Al-4V is a two phase alpha + beta grade of titanium and is the most widely used of all the titanium grades.