>>64252114
>Isn't a single piece of metal stronger than multiple pieces wielded together?
Not necessarily.
It's a lot harder to handle quality control on complex metal casting than, say forged or welded. Welds themselves are often very strong; the seams near the welds are the failure point. This is mitigated, and drastically so, by using (drum roll) good welders*. On the contrary, a cast metal part requires extremely specific conditions to allow the metal to crystallize (freeze/cool) exactly how you want it to.
Depending on the complexity of the part, it can be simpler, cheaper, or even more effective to just use a high quality bar stock and mill it to spec. In other cases it's easier to use that same high quality bar stock and "hide" the bends and welds needed to shape it appropriately.
All that said, even if welded metal is still weaker than a cast piece, sometimes you want to know HOW things will fail, and plan to engineer them in a way that they can fail acceptably. If you can transfer an explosion away from the vehicle, that's great. Barring that, if you can move it away from the crew and critical engine systems to, say, the muffler? That's a win right there as well.
All this is to say that there isn't a "right" answer about which manufacturing method is the best. It all depends on what you're building, how you're building it, and why you're building it. If you have a project that can be held up in quality control for three times as long as it's in production, that's one thing. If it needs to be churned out fast and you don't care if a few b-list units make it to market, that's another all together.
>*weld quality depends on things like the heating/cooling conditions of the surrounding metal prior to welding, the technique used to stack beads or create your seam, flux/infill, and whether you're using MIG, TIG, or stick welding for the types of metal you're tying together
