856A3774G03 is a precision-engineered aerospace engine high-pressure compressor (HPC) diffuser seal, compliant with AS9100D quality standards and FAA/EASA regulations, designed for CFM56-5 and CFM56-7 turbofan engines. It seals the gap between the HPC diffuser and the adjacent compressor casing, minimizing the leakage of compressed high-pressure air, which is critical for maintaining the air pressure at the diffuser outlet, ensuring efficient air delivery to the combustion chamber, and reducing the energy loss of the compression system.

Made from heat-resistant, high-strength nickel-based superalloy, it withstands operating temperatures up to 780°C and continuous high-pressure air impact. Weighing 0.17kg with a precision-machined sealing surface, it allows for fast installation and leak verification during HPC MRO overhauls. FAA Part 25 certified, it is a key component for HPC efficiency and engine operational stability.