There are two ways to make a camera body: carve it out of a block of aluminum or cast it in a steel mold. The molds are not ready yet, so the option exists to carve the camera bodies out of a billet of aluminum... one-at-a-time.
The industrial term for a mold is called tooling. The mold is cut on a CNC machine (kinda like a 5 axis router) out of tool steel that is hard enough and stable enough to have molten liquid aluminum poured into it tens of thousands of times in its lifespan.
It takes anywhere from 30 to 45 days to cut an industrial mold and build it into a production tool. -- They are articulated to aid in the release of the very hot, formed part.
If you have a Solidworks™ file of the body, you can feed instructions to the CNC machine ( hence: Machined )and cut the camera body out of a billet of metal in a matter of hours. These CNC machines (CNC= computer numerical control ) are expensive and can cost hundreds of thousands of dollars. The downside is you can only get about 1.25 camera bodies out of a single machine in a 24 hour period.
Molded bodies can be made in a single injection-molding machine at the rate of several hundred a day.
While the machined part is stronger, the strength is relative to the mission. A cast camera body will stand up to anything you can throw at it. The machined body is overly strong.


