Our strength

Connecting rod specialist

Market Share

We have about 50% market share in general purpose and small engine business in Japan.
We have 30 years of experience since in supplying our connecting rod to a major American air conditioning company.
We have a high reputation with our customers in the USA and Europe.

Quality control system

Because we are specialized in the connecting rod, we have been able to develop an original measuring method which remains unaffected by the tester after repeating improvements.
Since our operators are responsible for the quality check, our quality remains in the process.

Required Accuracy

Connecting rod is assembled with crankshaft by removing and restoring its big-End.
Great concern in this stage is stability (Circularity ) of big-End.
Irregular noise and/or Burn-in (Seizure) on inner face of hole might occur when above stability is imperfect. Thus, Stability (Circularity) is essential for connecting rod.

Over 70 years history

For more than 75 years, we have been started making our connecting rod since 1937.
Our long time operation is the result of our customers’ faith and support of our company since we specialize in the connecting rod, and we are able to imagine for our products what the drawing does not show.

A variety of variable production systems

We have production systems that can produce a wide range from one piece to several thousand connecting rods.


We have both general equipment and dedicated lines. We choose the line depending on the production lot and the material to use and the shape of the connecting rod.
We currently have 21 lines at our Toban plant.

Production capability

We produce 400,000 connecting rods per month with about 250 different types.

Reverse-engineering and development of prototype

We can make the required quantity by studying the original connecting rod without drawings.
We work with our customer from the development stage through the production of special applications like trial prototypes, and for racing.

Advise on materials

We recommend an appropriate material, taking into consideration, quantity, strength, shape, and budget.

Research and development

Our R&D is constantly trying to perfect our connecting rod for our customers.
Our aluminum fracture splitting connecting rod is a revolutionary, cost down production method compared to the standard production method.

Fracture Splitting Method

This method is inserting a stake into the big end hole and adding impact load to the stake. A fracture splits between the rod and the cap part.
The surface of each part has a brittle fracture convexo-concave, the positioning, like a clam shell alignment, can be found without fit processing.
We are experienced in the fracture splitting method of steel material, by strain-hardening through forging, and by low temperature brittle fracture through cooling.

Connecting rod delivery record

For general purpose/marine engine: We are currently supplying our connecting rod to USA and Japanese markets.
Major customers: Kawasaki Heavy Industries Ltd., Kubota Corporation, Fuji Heavy Industries Ltd., Honda Motor Co. Ltd., Yamaha Corporation, Tohatsu Corporation, Yanmar Co. Ltd.

For air conditioning, refrigeration and air compressor: We are currently supplying our connecting rod not only to Japan but also worldwide, including USA and European markets.
Major customers: Daikin Industries, Ltd. Hasegawa Refrigeration, Ltd. Mayekawa Manufacturing Co., Ltd, Mitsubishi Heavy Industries, Ltd. Carrier, Trane, Johnson Controls.