Spehro Pefhany wrote:

Recently I was shown a ~40lb aerospace part that started off weighting
more than 20 times as much. Believe it or not, it made sense to do it
that way, given the constraints.

I worked with a machinist who claimed to have
made a part for the space shuttle landing gear.
He said he started with a 200 lb billet of AL
and ended up with a 3 lb part. I'm thinking
that mistakes would get real costly in that line
of work...