system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 why are some metal objects cast while other are forged?
gpt
Depends on the application.

If the part is made in large quantities, then casting is probably more efficient and cheaper.if the part is very complex, then casting is also easier.

However, cast metal can be 'short' - meaning it has a crumb texture inside, like a shortbread. This can affect its strength.
Forged metal is usually tougher, so better suited for parts that carry a lot of stress.

Any industry that manufactures a metal part will weigh up the needs of the application versus cost, and figure out the best process.
It tends to be the case that cost cutting will result in parts being cast when they should have been forged. Cheap lever corkscrews...the handles always break because they have been cast and aren't tough enough for the physics of leverage.