The YKK initials found on zipper sliders in our clothes (Jeans pants, jackets) stands for Yoshida Kōgyō Kabushikikaisha (which roughly translates as Yoshida Company Limited) as per source. The YKK zipper manufacturing company was founded by Tadao Yoshida in Tokyo in 1934.
This answer to another question asked by curious students -
This answer to another question asked by curious students -
What is the full form of YKK in Zippers?
We can say that YKK is the short name of Yoshida Kōgyō Kabushikikaisha.
YKK zippers are manufactured by YKK Group and the company is based in Japan.
Before today, I never tried to find the full form of YKK zippers. It was assumed that YKK is the complete name of the zipper brand. I knew the zipper named YKK since my college days. When I was studying fashion technology in NIFT, I was given a class assignment to study various types of zippers and zipper brands.
It is not only me, most of the apparel industry professionals will agree with me that quality zipper means YKK zippers. We see the word YKK on the zipper sliders, to identify quality zipper.
Many apparel brands that make jackets having front opening zippers, Cargo pants, trousers, and other apparel items having zippers recommend using YKK zippers. Many apparel designers use YKK zippers.
Image credit: Images shown on the above slide are taken from other sources from the internet.
You can learn more about YKK Group by visiting https://www.ykkfastening.com/products/zipper/