3D Printing of metal parts

One thing to keep in mind when you consider any of the additive metal methods is the big hurdle in applying them: With a couple of promising exceptions, they can't produce parts from metals that are heat-treatable.

Any grade of aluminum (such as 6061, 2024, etc.) or of steel (1040 or above in carbon) that undergoes a hardening phase change won't work -- so far. So it's been limited to lower alloys or alloys that don't harden via a phase change.

For example, making injection molds and diecasting dies are *major* applications that the 3D people are working towards. But, so far, they've been limited to making them from maraging steel, which is expensive and less than ideal as a mold material.

But keep you eye on it. I was writing about it every couple of months when I was still working (at Fab Shop magazine), and you practically needed a program to keep up. It's moving really fast.