“Stainless Valve Ball” is used as the valve body of the“Stainless Ball Valve”, and has more than 60% of the domestic top share.

The Strength of Kida Valve Ball for spherical parts of medical hip joint

The strength of our company is “the ultra-precision sphere processing technology (spherical processing technology extremed in surface smoothness and high sphericity.) This is our unique technology developed by more than half a century of valve ball manufacturing performances. In general, there are not many companies that possess highly accurate technique of both cutting works and polishing works. We have been improving the accuracy of sphericity and surface roughness by developing unique in-house facilities for the sphere polishing process.

  • Our Original Facilities

    ・Dedicated lathe for spherical surface ・Dedicated polishing machine for spherical surface. ・Dedicated lapping machine for spherical surface. ・Dedicated buffing machine for spherical surface.
  • Our Original Grindstones

    ・Cylindrical WA/GC/Diamond Borazon ・Cup WA/GC/ Diamond Borazon

Leveraging this technology, we are working on the development and OEM manufacturing of the“spherical parts of medical hip joint”endoprosthesis, outer cup and bipolar from 14 years ago. Accumulated actual total distribution is 14,000 sets. From these actual performances, we would like to recruit joint partners for hip joint and dialyzer parts overseas as well, just like in Japan. (Domestic actual performance: supplying products to the three major manufacturers.)

High Quality Sphere Processing Accuracy

Achievement of a good balance between spherical accuracy and surface roughness had enabled us to manufacture an ultra-high precision endoprosthesis. The balance between the two are a tradeoff relationship that if one side’s accuracy is pursuit, the counterpart’s accuracy becomes rough which complicates the achievement of the both. Our company had pursuit the accuracy of both side to the limit as much as possible, and had achieved the means for the mass production.

Comparison of sphericity and surface roughness accuracy.*Metal material (Cobalt-chronium alloy)
Kida Valve Ball Products Other Company’s Products
Sphericity Accuracy 0.1~0.3micron 1.5~3.0micron
Surface Roughness Ra0.01~0.03micron Ra0.06~0.10micron

Whatever Material Can be Rounded. Recently, we are replacing special resin to metal material for some manufacturing and development. We are flexibly accommodating to manufacturer’s new material product development. This is possible because we can manufacture almost all possible commercial materials in valve ball manufacturing

Table of Materials

Austenitic Stainless(SUS303・SUS304・SUS304L・SUS316・SUS316L・SUS317,etc.) Martensitic Stainless(SUS630・SUS403・SUS440C,etc.) Duplex Stainless(SUS329J1・SUS329J4・254SMO,etc.) Iron in General(SS・S45C・SUJ2・SCM435,etc.) Brass、Aluminum、Monel、Carpenter、Inconel、Metco 16C、Incoloy、Colmonoy、Zirconium、Kovar Gunmetal、Titanium、Hastelloy、Tantalum、Ceramic、Stellite、Tungsten Carbide、Cobalt Chrome、Magnesium、Aluminum Bronze

Integrated Manufacturing Process

  • ①Forging

    We excel at press cutting, press production (hot forging), mainly with stainless steel material. We provide high-mix low-volume products in short delivery time, low price with high quality. (One unit weight from 0.2kg to 15kg, outer diameter from 50Φ to 250Φ).
  • ②Sphere Cutting

    ②Sphere Cutting
    We make full use of our original sphere processing machine (lathe, polishing, lapping) to provide spheres and cutting process parts of the world’s highest level.
  • ③Spherical Polishing

    ③Spherical Polishing
    Spherical polishing is performed utilizing our original machineries such as spherical cylindrical polisher, spherical cup polisher and spherical lapping board to achieve precision limit, sphericity accuracy of less than 1μm and ultra-high accuracy in surface roughness of less than Ra 0.03 leveraging our long years of process experience and accumulated know-how.
  • ④Spherical Buffing Process

    ④Spherical Buffing Process
    Spherical buff polishing is a very difficult process, and specially, the working process to buff surface roughness to mirror finishing while maintaining spherical accuracy is unique to our own. Using several kinds of buffs and polishing materials enables our ultra-high sphericity (sphericity accuracy + surface roughness).
  • ⑤Inspection

    In response to our customer’s request who particularly requires accuracy, we perform accuracy inspection from various aspect and only release what we can receive 100% confidence from our customers.
  • ⑥Packing and Shipment

    ⑥Packing and Shipment
    We use our original dedicated polyethylene tray for the valve balls to avoid interference during the delivery of the products. We pack them one by one carefully to deliver safe products to our customers.