Cessna gear brackets and inboard angles are manufactured using an extrusion process which is geared for high volume, lower cost production. As the aluminum is extruded the molecular structure of the material is altered which makes it more susceptible to developing inter-granular corrosion. Shown here is a top view of an outboard gear bracket with severe inter-granular corrosion. Note how the material expands and flakes off in layers. This is due to the re-alignment of the molecular structure that occurs during the extrusion process. Parts milled from cold rolled aluminum block do not develop this type of destructive corrosion.