Product Lineup

"Products that could only be developed with the fastening experience of
Aoyama Seisakusho..."

Aoyama Seisakusho is developing core fastener technologies to create new value for our customers. Our products, which are borne of Aoyama's unique ideas and technologies, are used in every area of the vehicle. We are realizing solutions for our customers, anticipating their needs and improving vehicle quality.
This is Aoyama Seisakusho's "Value-added Manufacturing".

Interior parts

  • Plastic

    Ergo Grommet

    Easy to assemble screw grommets.

  • Plastic inserted

    Utility Fasteers

    Metal and plastic combined fasteners.

  • Plastic

    Design bolt

    Design bolt for increasing luxury,

Exterior parts

  • Bolt

    Fit-weld bolt

    Weld bolt with water sealing function after wendling.

  • Bolt


    Thread forming screw for the plastic with easy direct assembly without cracking fixing parts.

  • Plastic inserted

    Open Weld Nut

    Plastic lid on top of the nut eliminates the masking process.

  • Plastic inserted

    Sealing washer

    Washer with the water sealing function without loss of clamping force.

  • Plastic inserted

    Plastic inserted pivot bolt

    Plastic inserting of metal pivot head prevents fixing parts from scratching.

  • Plastic inserted

    Garnish bolt

    Complete insulating by plastinc insertion together with rigid fastening and sealing function.

  • Plastic inserted

    Insulator clip

    Without tools, easy-to-assemble clip that prevents galvanic corrosion that may result insulator falling off.

Upper body parts

  • Bolt


    The bolts that self-align an angle when fastening.

  • Tapping screw

    ET Screw®

    Easy to assemble thread froming screw for sheet metals.

  • Nut

    Piercing nut

    Environment friendly piercing nuts can be clinched during stamping process and eliminates welding process.

  • Plastic inserted


    Bolts with sealing and anti-scratching function.

  • Plastic inserted

    Spare tire clamp

    Easy to handle, recycling efficient fasteners.

  • Plastic inserted

    Space adjust®

    Fasteners adjusting the space between fixing parts.

  • Bolt

    R Navitite®

    Bolt that prevents cross-threading due to misaligned fastening.

Under body, Chassis parts

  • Bolt

    ND Bolt

    Serrated portion under head holds washer from wobbling.

  • Nut

    Tri-cut nut

    Nut with paint scraping flutes on the thread.

  • Nut

    High strength weld nut

    Weld nut for high tensile strength bolt.

  • Surface treatment


    In-house developed friction coefficient stabilizer.

  • Bolt

    Fluted R Navitite®

    R Navitit with the pait and the welding spatter removing function.

  • Bolt

    Wheel hub bolt & nut

    Critical items like hub bolt and hub nut are available.

  • Nut

    Aluminum bolt & nut

    Bolt with aluminum washer for protection from galvanic corrosion.

  • Nut


    Special designed flange nut for increasing stability.

  • Bolt

    High strength bolt

    High strength bolts with 1600MPa capability.

Engine / Drivetrain parts

  • Bolt

    Cylinder head / crank cap bolt

    Achieving high clamping force by plastic region fastening.

  • Bolt

    Connecting rod bolt

    High strength bolt having excellent fatigue characteristic.

  • Nut

    Slit lock nut

    Specially designed slit on top of the nuts for the locking feature.

  • Bolt

    Aluminum bolt

    Aluminum bolts suitable for the weight saving..


  • Bolt


    Press fiting stad bolt suitable for muti-material fastening.

  • Nut

    Piearcing nut with lid

    Specially designed nut suitable for bus-bar joint with preventing foreign particle from fallin off.

  • Collar

    Insert collar for plastic

    Inexpensive insert collar with high holding force.

  • Precision cold formed parts

    Positive & Nagative terminals

    Noferrous metal such as copper and aluminum also available. Throughly prepared for contorl of contamination.

  • Clinching items


    Clinching nut without needs of making hole, preventing foreign particle.

  • Screw


    Specially designed head shape for easy assembley, suitable for automated fastening.

  • Screw


    Specially designed head shape for easy assembley, suitable for automated fastening.

  • Function parts

    Breather plug

    Parts for adjusting interal pressure of parts. It prevents oil leaking, and creates air path when rolling over.

  • Surface treatment

    Whisker-less plating

    Surface treatments that restrain whisker, suitable for electric parts.

  • Bolt

    Low head bolt

    Shallow head desin for weight reduction and securing space inside units.Head strengh is designed to meet required strength.