You still don't choose forging as a process to make quantity 2 (unless you absolutely need forged parts for strength). Instead, you're milling two parts from billet.
Milling 2 parts from billet is cheaper per unit than milling 1 (some shared setup and programming costs), but it's the same amount of raw material and basically the same amount of operator time.
Re:James Webb is fully deployed
by WalterBright on Saturday January 08, 2022 @05:09PM
(#29856924)
You're right that a one-off forging is so expensive that a hogout will be used instead. My point was how expensive one-offs can be compared to multiple ones, and I used extreme examples as illustrative.
Even in custom machine work, the cost is in the setup. A machinist can make two identical cuts on two parts for not much more cost than one cut on one part.
When I worked at Boeing, the first forging of a part cost $250,000. The next, just a handful of dollars.
At Boeing, the first airplane gets a ton of testing, as the design is being tested. Airplanes #2 and on only get tested to verify it was built according to the design, at a tiny fraction of the cost of testing #1.