What are Macbook Pros made out of?

The previous MacBook Pro uses a thin, bowl-shaped shell that has an internal skeleton to hold the internal parts together. The top bezel lays on top and is screwed in place on the sides and back edge. These pieces allow for some tolerance, requiring plastic gaskets to fit the components together snugly.

The new 15" MacBook Pro, along with its nearly identical 13.3" MacBook version, start with an extruded block of aluminum that is carved out using CNC or "computer numerical control" machines in a process used by the aerospace industry to build mission critical, high precision components.