Keystone is actively developing and applying methods for solid-state joining of aluminum and titanium alloy structures. Keystone is pioneering titanium joining methods using a NASA invented Thermal Stir Joining process that is proving effective for long tool life and microstructural control of the stirred metal. Keystone is applying this capability to the fabrication of advanced integrated airframe structures and to the fabrication of mega-yacht hulls and structure.

Keystone has developed stir conversion methods for the rejuvenation of fusion welds and the tailoring of microstructures for manufacturing and repair applications.