Koyo， KOYO SEIKO, founded in 1921. It is a Japanese manufacturing enterprise with 6557 employees. It is one of the four major bearing production groups in Japan, with world-class production and control equipment. It has eight main production factories in Japan, including Tokyo, Nara, Yinda, Toyokazu, Takamatsu, Tokushima, and Guishan (all certified by ISO9001), and several production bases and research institutions across Europe, Asia, North and South America.

Guangyang Seiko Co., Ltd. and Toyota Koji Co., Ltd. merged on January 1, 2006 to form a new company called JTEKT Corporation.

Koyo's main products include rolling bearings, deep groove ball bearings, high-precision bearings, self-aligning bearings, seat bearings, flat ball bearings, short cylindrical roller bearings, linear guide bearings, ball screw bearings, miniature linear guide bearings, cross roller guide bearings, reciprocating sleeve bearings, ball sliding group bearings, and cam driven bearings.