So he returned to thread-rolling to try to revamp a century-old process.

FORBES: Magazine Article

Meanwhile, he grabbed an old thread-rolling machine out of a nearby factory and wired it to operate very slowly to let him observe exactly what was happening.

FORBES: Magazine Article

Manipulating the shape of the threads using this method, called thread-rolling, was thought to be impossible because it would be too hard to control the structure of the screw if metal oozed into odd shapes.

FORBES: Magazine Article