why all zippers have "YKK" on them

i've always wondered that.
Why Zippers Have YKK On Them
The YKK stands for Yoshida Kogyo Kabushikikaisha (say that five times fast). In 1934 Tadao Yoshida founded Yoshida Kogyo Kabushikikaisha (translated Yoshida Industries Limited). This company is now the worlds foremost zipper manufacturer, making about 90% of all zippers in over 206 facilities in 52 countries. In fact, they not only make the zippers, they also make the machines that make the zippers; no word on if they make the machines that make the parts that make up the machines that make the zippers.

Their largest factory in Georgia makes over 7 million zippers per day.
via