Initially, they performed simple processes like cutting straight pipes, but gradually expanded their processing capabilities to handle complex operations. Now, they can handle pipe processing from cutting and chamfering to bending, drilling, copper brazing, and leak testing, all in one stop.
Many small companies performing pipe processing specialize in only a few processes, such as cutting or bending. However, at Kohgen Tekko, as long as they have the raw pipe material, they can handle everything except surface treatments (such as plating).

A turning point in their pipe processing was the introduction of a copper brazing furnace.
When they first received a request, they considered outsourcing because they didn't have a furnace.
Although Hisayoshi hesitated, he decided to invest in a very expensive furnace.
In oxygen-free furnace brazing, copper is wrapped around an iron pipe and heat is applied. Copper melts at 1080 degrees Celsius, but iron does not. Materials are passed through a furnace heated to 1150 degrees Celsius, melting only the copper for brazing. Since the furnace is oxygen-free, the iron does not oxidize even when heated.

As such, because it is a special furnace, clients consequently increased their copper brazing orders and began to entrust most of their work to Kohgen Tekko.
This established Kohgen Tekko's strength in providing one-stop pipe processing.

Many of the pipes manufactured at Kohgen Tekko are used in automotive engine parts. In the case of pipes carrying coolant, a leak can cause the car to overheat.
The engine compartment contains various parts. Pipes are integrated into these spaces, resulting in very complex shapes.

Furthermore, even a slight misalignment of the stay for tightening bolts can prevent installation.
The part that attaches to rubber hoses requires careful end processing, as damaging the rubber can cause it to break and lead to water leakage.
In pipe processing, meticulous attention to various details and high precision are essential.

Therefore, precise bending with a tight radius requires skill.
Moreover, JIS standards allow for a pipe diameter tolerance of approximately 0.1 to 0.2 mm. For products processed by Kohgen Tekko, this must be reduced to 0.05 mm.

Furthermore, if the tolerance is too low, the die cannot be properly clamped during processing, preventing dimensional accuracy.
"When we consulted the machine manufacturer, they told us to replace about three types of dies to handle it. But that would lower productivity."
So, they consulted with the pipe manufacturer and requested that the pipes delivered to Kohgen Tekko have only positive tolerances.

The bending angle for pipes is input into an NC bender.
However, due to springback, setting it to 90 degrees does not mean it will bend exactly 90 degrees. Adjustments are made to achieve the correct angle after calculating the error.
Moreover, these adjustments must be changed depending on the material lot.
"The thickness of the steel plate used to make the pipes themselves varies."
If the thickness of the steel plate used for the pipes differs, the degree of springback also changes. Discerning this and making appropriate adjustments likely requires extensive experience.
"We have accumulated various techniques over about 20 years, adapting to each situation."

Even now, it is said that it takes about 20 years to master all pipe processing techniques.
This is because bending has its own techniques, and brazing has its own techniques.
Kohgen Tekko has accumulated these techniques one by one. It is precisely because of this accumulation that they can select the optimal processing method depending on the pipe's shape.
"While any pipe angle can be drawn on a drawing, whether it can actually be processed is another matter."
The ability to make judgments from drawings and advise designers also comes from accumulating extensive know-how.

To maintain product quality, they implement quality maintenance curricula and formulate annual plans.
In addition, they pay attention to quality maintenance by using cameras to check areas that are difficult to verify with the human eye.
They also manage and adjust rust-preventive film thickness for outsourced surface treatments and conduct pipe leak tests in-house.

While sparing no effort to maintain quality, they also diligently work to reduce costs.
They are promoting automation where possible so that part-time employees can perform tasks to a certain extent, and they are also creating jigs that simplify operations.
"The previous generation performed round bar machining. They had the ingenuity to devise ways to process without deviation."
It is said that customers sometimes visited to observe the processing and ask questions.
This attitude of striving for better manufacturing through ingenuity is likely inherited in this way.

"Looking at the automotive industry, internal combustion engines will disappear and be replaced by electric vehicles."
They predict that the demand for the pipe parts they currently produce will decrease, and they feel a sense of crisis about the future.
Therefore, Kohgen Tekko is exploring new core businesses that do not solely rely on the automotive industry.

"While there are many jobs that provide services, I only know manufacturing, and I love manufacturing."
Kohgen Tekko, which started with round bar machining, has also cultivated machining techniques. Of course, they also have techniques cultivated through various pipe processing steps.
And above all, they have a passion for manufacturing and the ingenuity to create better products.
It is precisely because of Kohgen Tekko's nature that we might see them active on a new stage in a few years.