A giant, high-speed 3D printer is producing large ultra-strong steel components and weapons for the US Army. It may also have applications outside of the military.

The prototype printer, commissioned from 3D Systems of Rock Hill, South Carolina for $15m, can create objects up to a volume of 1 by 1 by 0.6 metres. The makers call it the largest, fastest and most precise steel printer ever made, big enough to print entire parts for military vehicles, such as hatches. …