Factory Guide

Since the balls have only been compressed, they still have ridges or protrusions called 'burrs.' Depending on the size of the balls being produced, up to approximately 1,000 balls can be produced per minute.

This process removes the burrs formed during heading and smooths out the surface of the balls. At this point, the surface still appears rough as only the burrs have been removed.

By heating the balls to over 800°C and cooling them rapidly, the structure of the steel changes and hardens—this process is called 'quenching.' Since the balls remain brittle after quenching, they are reheated to high temperatures for 'tempering,' which strengthens them.

In the flashing process in STEP02, a “metal plate” is used to grind the balls, but in the fine grinding process, a “grinding wheel” is used to improve the accuracy of the finished product. The surface becomes smoother than in the flashing process.
In the first lapping process, the balls are further refined and finished to a predetermined dimensional tolerance. The ball is processed with a grindstone of finer grain than in the fine grinding process to further improve the accuracy of the ball and stabilize its quality.

The balls’ precision is improved to grade-level standards and the ball's surface is polished to a mirror-like smoothness. Even finer-grain grinding wheels are used compared to the first lapping. Via repeated polishing, the balls are shaped into perfect spheres with an even glossier finish.