[Development secret story] Realizing Japan's first black-plated pliers and nippers with the pride of a top brand

Aiming for perfect plating, repeating trial and error

ーーKUROKIN What was the most important point in developing the ?

Sato : Pliers and nippers are plated.
Our company has a domestic market share Four Top brand of pliers and nippers that boasts competitive strength.
That's why we stuck to plating even if it cost more.
It took a lot of effort to achieve a luxurious black color.

Ota : It is difficult to apply black plating to cutlery tools such as pliers and nippers, and this is our first attempt.
At the stage of small-lot production, things were going well, so at first I thought it would be possible. 70% There were times when things went wrong.

ーーWhat kind of problems did you have?

Sato : After the body of the pliers and nippers is completed, we bring them to a plating shop for plating.
But at first, the plating didn't adhere well, and when I opened and closed the pliers, the plating around the rivets (joints) came off.

Ota : As a result of talking with the plating shop, one reason came to mind that the cleaning before plating was not good.
Normally, the cleaning would be done by a plating shop, but under the cleaning conditions of the washing machine that the plating shop has, there may be problems with opening and closing the pliers and nippers, oil may remain in the gaps between the rivets, etc. Fine dust adhered to the surface, and the plating did not adhere well.

Sato : Therefore, we introduced a powerful washing machine and made it in-house.
However, if the plating is not applied immediately after cleaning, the surface will rust.
It was also difficult to manage the process, such as when the plating work could start, the cleaning work should be finished by what time, and the products should be brought in immediately.

Ota : In order to do as much as possible in terms of design, we also reviewed the shape of the rivets and made improvements such as making larger grooves to prevent the plating from peeling off.

2 Twisting my head at the company and clearing difficult problems one by one

ーーIt must have been a lot of work just to do the plating.

Ota : Pliers and nippers are especially difficult because the thickness of the cutting edge varies depending on the part and it opens and closes.
Due to the characteristics of plating, there were times when plating pools were formed on the cutting edge.
There is no problem at the stage of completion, but when I try to cut it, it comes off.
The reason is the thickness of the plating.
If it is too thick, plating deposits will occur, and if it is too thin, the color will not stick and it will easily rust.
We made many prototypes to find the perfect balance by devising the setting conditions for the plating when controlling the thickness and depositing the plating.

Sato : There was also the problem of the baking coming back.
The blade is strengthened by baking it at a high temperature and then cooling it with water or oil, but the blade becomes soft when heat is applied again when it is washed before plating.
Currently, I am avoiding it by adjusting the temperature control of washing, but if I suppress the heat and wash it, it will not be clean, so I repeated trial and error ... I really struggled with washing!

Ota : Just when you think one problem is solved, another one pops up.
For problems that come up one after another, it is difficult to find out which process is the cause, whether it is the manufacturing stage of the product, cleaning, or plating.
No wonder other manufacturers don't do plating (laughs).

Sato : You may think that it's just a change of color, but it's no good if the size is different even if it's the same variety.
Pliers are fine, but nippers are useless. Last time it worked, but this time it didn't.
And so on, anyway, it's hard.
Even if rival manufacturers tried to make the same thing, they would not be able to do it.

The challenge continues to meet the expectations of craftsmen

ーーHow long did it take to develop?

Ota : For about a year, we rearranged the process.
However, about a year after its release, the plating shop changed. After many adjustments, the production environment that was finally created changed, and I had to adjust it again from scratch.

Sato : Because sales were growing and production couldn't keep up.
It's a happy scream. The first plating shop I asked for can only produce in a month. 1500 Ding degree.
We have exceeded the plating shop's capacity, so we can't put any more burden on them.
So, I consulted with a large-scale plating shop and decided to put in place a system that would allow us to produce a larger number of products.
The plating itself is a specially formulated product, so it was the first time for the plating shop to handle it, and fine adjustments were necessary.
There were varieties that were doing well at that plating shop, but not at this plating shop... and vice versa.

Ota : On the other hand, it is quite popular in the market and is in short supply. So this year KUROKIN I had a dedicated production line made, and in the month 7000 I asked them to create a system that could produce as much as a ding.

ーーAnd now it's finally completed KUROKIN That's right.

Sato : No no. Not complete yet. In fact, even now, all products are inspected, and when there are many 20% may not meet the standards and may be discarded.
KUROKIN With other products, it is unlikely that defective products will appear after the plating process.
Plating can make the opening and closing harder, so we also adjust it manually when checking.
That's why we are still discussing with the plating shop and our quality control department and continuing to make improvements to increase the accuracy.

ーーWhy are you spending so much manpower and money on development?

Sato : After all, it is because the craftsmen are pleased.
SNS There are many people who upload photos to and boast about it. Being able to make pliers and nippers like this is a great privilege for a manufacturer.
We will continue to take pride in being a top brand and continue to live up to their expectations.