The AMS 4943 Specification
AMS 4943 is the aerospace material specification for welded titanium alloy tubing in Grade 9, Ti-3Al-2.5V. The specification defines the composition, mechanical properties, dimensions and testing requirements for the welded tubing used in aerospace fluid systems. Grade 9 titanium alloy possesses excellent comprehensive properties, including high strength, low density and good corrosion resistance, and its weldability makes it the standard alloy for welded aerospace tubing. The AMS designation means the material meets the quality and traceability requirements of the aerospace industry.
Technical Specifications
Grade 9 welded pipe is produced to the applicable standards including ASTM B338 and ASTM B861 in addition to AMS 4943, and it is available in seamless, welded and drawn forms. The outer diameter range is 6 to 114 mm, the wall thickness 0.5 to 6 mm, and the length up to 6000 mm or custom. The density is 4.48 g/cm³, the minimum tensile strength about 620 MPa, the minimum yield strength about 483 MPa and the elongation at least 15 percent. The surface finishes include polished, pickled and sandblasted, selected by the application.
Chemical Composition
The composition of Grade 9 is controlled within tight limits: nitrogen 0.03 percent maximum, carbon 0.08 percent maximum, hydrogen 0.015 percent maximum, iron 0.25 percent maximum, oxygen 0.15 percent maximum, aluminum 2.5 to 3.5 percent and vanadium 2.0 to 3.0 percent, with the balance titanium. The aluminum stabilizes the alpha phase and raises the strength, and the vanadium stabilizes the beta phase and improves the workability. The low oxygen and hydrogen limits preserve the ductility and weldability of the alloy.
Mechanical Properties
The mechanical properties of Grade 9 are verified by tensile testing. The annealed condition provides a minimum tensile strength of about 620 MPa with a yield strength of about 483 MPa and an elongation of at least 15 percent, and the higher-strength conditions reach a tensile strength of about 860 MPa with a yield of about 725 MPa. The strength-ductility balance makes the alloy suitable for hydraulic, pneumatic and fuel systems, where the tubing must be formed, welded and pressure-tested in service.
Applications
AMS 4943 Grade 9 welded pipe serves aerospace hydraulic systems, fuel lines and pneumatic ducting, and the same alloy is used in bicycle frames, heat exchangers, chemical processing systems and automotive exhaust systems. The welded form offers cost advantages over seamless for many sizes, and the weld quality is verified by non-destructive testing. The alloy's seawater corrosion resistance makes it suitable for marine systems, and its combination of strength and weight saving suits high-performance applications.
FAQ
Q: What is AMS 4943?
A: The aerospace material specification for Grade 9 titanium alloy welded tubing.
Q: What is the composition of Grade 9?
A: 2.5 to 3.5 percent aluminum and 2.0 to 3.0 percent vanadium, with the balance titanium.
Q: What are the annealed mechanical properties?
A: Tensile strength of about 620 MPa minimum, yield of about 483 MPa and elongation of at least 15 percent.
Q: What sizes are available?
A: Outer diameters of 6 to 114 mm with wall thicknesses of 0.5 to 6 mm.
Q: Where is AMS 4943 welded pipe used?
A: Aerospace hydraulic, fuel and pneumatic systems, plus industrial applications requiring the same properties.
Contact us for AMS 4943 Grade 9 titanium welded pipe with aerospace certification for your fluid system.
