[RedBallJet]

There are myriad material heat treatments for steels and metals such as flame hardening, case hardening, induction heat treatments, nitriding, annealing, normalizing, tempering, carburizing, oil hardening and quenchings.

With those processes being integral to the overall manufacturing processes of machine tools and the parts they’re designed and engineered to produce, no 3D printing process can be employed in the manufacture of those kinds of parts as finished products.

It’s too easy to fall in love with some of the new technology and in the rush to abandon traditional proven techniques and processes, foolish assumptions can easily made.

[St_Thomas_Aquinas]

There are myriad material heat treatments for steels and metals such as flame hardening, case hardening, induction heat treatments, nitriding, annealing, normalizing, tempering, carburizing, oil hardening and quenchings.

Metallurgy is a science of its own. It's especially important for high-stress applications, like guns and canons.

[aimhigh]

no 3D printing process can be employed in the manufacture of those kinds of parts as finished products.

A company called ARCAM AB, in Sweden, makes 3D printers that create objects from titanium, using an election beam.