Five years ago, it would have seemed an unlikely partnership. But the alliance announced today between BHP Billiton, the world’s largest mining group, and printing technology company Hewlett Packard, makes perfect sense.

And the reason? 3-D printing has gone mainstream as an industrial production technique, and HP-BHP wants to corner the market.

There’s hardly an industry within which 3-D printing is not hard at work, from construction to aerospace. And the demand for the specialized metal powders – like titanium, chrome, and molybdenum – to feed the printers has skyrocketed.

Thus BHP (and a few innovative other mining houses) quickly recognized the potential of this new market, and bought into startup companies producing printable powders, to develop new markets for the metals they mine.

Meanwhile, HP was pouring tens of millions into becoming a leading player in producing 3-D printers, from tiny home gadgets to massive, high-end industrial machines. It was a marriage made in… well, made in a 3-D printer! Just like ink-jets, consumer metal printers are sold below cost; the profits are made in the high tech, high priced metal powder refills.

Experts are predicting virtually unlimited demand for the new powders, as everything from jewelry to turbine blades are churned out of the metal printers. And one side effect is that traditional manufacturing has gone into a slump, as the cost of 3-D printing falls lower and lower.