What does the material code letter 'D' following the AN number represent?

In the context of AN (Aerospace Standard) fittings, the material code letter 'D' indicates that the fitting is made of steel. This is significant in applications where the strength, durability, and corrosion resistance of fittings are crucial considerations, particularly in aerospace and automotive industries.

Understanding these material codes is essential for ensuring compatibility and performance in various environments. Steel fittings are often preferred for their tensile strength and ability to withstand high-pressure situations and harsh conditions. This knowledge helps professionals in the field choose the appropriate fittings for their specific applications, ensuring optimal performance and safety in fluid line systems.