These machines were perfected in the '60s and '70s. They are not only exceptional for their ability to make a hole perfectly located and perfectly sized, but al

These machines were perfected in the '60s and '70s. They are not only exceptional for their ability to make a hole perfectly located and perfectly sized, but also for making it perfectly round. Their ways being perfectly straight and perpendicular, and metallurgically stable, they are often bought just as a platform for converting into special tooling (for making air bearings, diffraction gratings, metrology and semiconductor equipment, and so on).