@nony - A directional solidification system makes sense. The question is, in what environments do they use this process? If you are talking about going down to the local home improvement store, I can understand how you can find the stray metal piece that isn’t developed quite right.
I doubt they use directional solidification of steel castings in this context, because it really doesn’t matter for do it yourself projects.
However, if you’re building pieces that are going to be used in aircraft wings, for the purposes of providing support, I’d bet they are using directional solidification for those parts. I’ve heard of wings falling off (or flaps anyway) because of a defect in a ball bearing or some other metal piece.