One way to optimize CNC manufacturing is to cast a metal part then finish mill it. The casting creates a blank which takes care of most of the metal removal that a CNC job from billet stock would (time really = money in CNC). The CNC passes are mostly finish passes to mill out accurate features with the desired surface quality.
Some metal slides are CNC'd from cast blanks. While the critical features are accurate (rail grooves etc) their material will not be as strong as age hardened 6xxx or 7xxx aluminum billet stock. Still, I've never seen a broken CNC'd slide yet.
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