FRANKFORT, Ky. (AP) — Apple on Tuesday deepened its ties with a Kentucky manufacturing plant by awarding $250 million to support Corning Inc.’s continued work to develop glass for iPhones and other devices.

The award builds on the $200 million that Corning received from Apple’s Advanced Manufacturing Fund in 2017, the tech giant said. The combined investments support Corning’s research and development that will be crucial for next-generation consumer devices, Apple said.

Scratch-resistant glass for every generation of iPhone has been made at Corning’s plant in Harrodsburg, Kentucky. Corning also supplies glass for iPads and Apple Watches.

“Apple and Corning’s rich history dates back more than a decade and our partnership revolutionized glass and transformed the technology industry with the first iPhone,” Jeff Williams, Apple’s chief operating officer, said in a release.

“This award underscores Apple and Corning’s shared belief in the vital role that ingenuity plays in creating industry-leading products, and the pride that both companies take in applying American innovation and advanced manufacturing to solve some of the world’s toughest technology challenges,” he added.

Wendell P. Weeks, Corning’s chairman, chief executive officer and president, said the additional investment will allow the Corning, New York-based company to develop “groundbreaking new glass innovations” while expanding its manufacturing capabilities.

“Most importantly, our ongoing collaboration allows us to create vital new capabilities for end users and continue pushing the boundaries of what is possible well into the future,” he said.

Corning employs about 400 people at its technology development and manufacturing operations in Harrodsburg. It’s been part of the central Kentucky community for more than 65 years.