Product Development Story 1

"TIGHTNIK" anti-loosening washer

Our company founder and developer, Toshiyuki Kato.

He loves the craftsmanship of wooden construction and often went to construction sites.

One day, a craftsman told him about a problem he was having at a construction site.

The lumber is a very good material, but when it shrinks due to drying, the bolts and nuts loosen and the strength of the building is reduced.

However, once the building is completed, it is not possible to retighten the bolts and nuts hidden by walls.

He was asked to come up with a product that would solve this problem.

This was the trigger for the development of the product.

After thinking about it for about a year, the principle of inserting a ring-shaped wedge between the bolt and washer

and continuously pushing the wedge ring with a spring to follow the shrinking lumber, flashed in my mind,

and we commercialized the product.

Thanks to the support of our customers, we have sold more than 100 million units in total.

Lumber, even dry lumber, always shrinks over a long period of time.

We were able to develop a product that can contribute to the wooden construction industry through the suggestion of craftsmen who know the construction site inside and out.