Our Products

Our Technology that Supports Transportation Equipment and Industrial Machinery

Many springs are at work outside the limelight of our day-to-day lives to cushion shock and vibration and to make equipment and devices function safely. Among these springs, we at Sumihatsu are one of the leading domestic manufacturers that can manufacture large springs by hot forming. Our products are used to support heavy-duty transportation equipment and industrial machinery.

Sumihatsu Products
in Day-to-Day Life

  • Leaf Spring

    Trucks / Buses /

    Leaf Spring Used for Trucks and Buses:
    Top Share in the Domestic Market

    Including suspensions that absorb vibrations transmitted from the road to reduce their impact on drivers, passengers, and cargo, many domestic truck manufacturers use leaf springs manufactured by us at Sumihatsu.

  • Leaf Spring

    Steam Locomotives

    Heavy leaf springs (bearing springs)
    that support the horsepower of steam locomotives

    The restoration of steam locomotives is ongoing in various places due to regional revitalization projects and the like. Since available detailed drawings at the time of steam locomotives are few, we design and manufacture them by checking the actual article and meeting with the customer.

  • Leaf Spring

    Rally Cars

    Involved in tuning leaf springs for rally cars in addition to commercial pickup trucks

    In order to meet the demands of our rally team customers, we strive for leaf springs that are stronger and lighter. We take care of everything from design right through to manufacturing, while constantly improving our skills to help them secure first place on the podium.

  • Leaf Spring Coil Spring Railway


    Three Hidden Springs
    that Support Elevators

    Fastening leaf springs, for which rail technology is applied, are used for the guide rails that stabilize the movement of elevators. In addition, the U-spring is used as a speed control / stop device in the event of an emergency, and the coil springs installed in the bottom layer play the role of cushions.

  • Coil Spring

    Excavators &

    Force of Springs: Acting inside the Crawlers of Heavy Equipment Indispensable for Construction Sites

    Construction machinery that exerts immense power even on unstable scaffolds. Coil springs support your feet to prevent the crawlers from detaching and to reduce the impact transmitted to the body of the vehicle.

  • Coil Spring

    Industrial Robots

    Contribute to Labor-saving and Automation in Manufacturing Industry through Arms of Industrial Robots

    Automation is advancing in manufacturing plants of a whole host of industries. Springs that assist the torque load of the motor are essential for producing the quick and precise movements of industrial robots.

  • Coil Spring

    Trains & Shinkansen
    Bullet Trains

    Coil Springs Improve the Riding Comfort of Railway Vehicles from Regular Trains to Shinkansen Bullet Trains

    By virtue of the action of springs which support the bottoms of vehicles, you can use trains for daily commuting and/or shorten travel times by traveling at high speeds.

  • Coil Spring


    Our Springs are also
    Used on Japanese Rockets

    We were involved in a space project that unites the latest Japanese technologies. Our repeated trial and error efforts made it possible to manufacture springs that function accurately in a harsh environment, which is different from that of earth, as well to comply with the weight standards.

  • Railway


    Turnout that Branches the Rail Track and Switches the Course of railway vehicles

    We handle everything from design right through to manufacturing and assembly. As a successor of Yamamoto Hatsujo Bunki, Inc., we are the oldest turnout manufacturer in Japan.

  • Railway

    Rail Tracks

    Manufacturing a Broad Range of Products from New Parts to Replacement Parts

    We manufacture parts that make up rail tracks, such as resin sleepers and devices that suppress the vertical movement of rails. The device that fastens the sleepers and rails is made of springs to withstand vibrations.

  • Coil Spring Railway


    Balancer that Keeps the Tension
    Constant so that the Railway Wires do not Droop Down

    The tension of the railway wires, which come into contact with the train’s pantograph, changes depending on the temperature. The spring-type balancer absorbs the expansion and contraction of wires, automatically adjusts the tension to a constant value, and is maintenance-free.