TOYOTA 90105-08100 Flange Bolt

The Toyota 90105-08100 is a high-strength, genuine OEM flange bolt specifically engineered to meet the stringent structural and fastening requirements of Toyota and Lexus vehicles. The flanged design acts as an integrated washer, distributing clamping force evenly across mating surfaces to prevent material deformation and provide maximum holding power under severe vibration.

Technical Features and Specifications:

• Manufacturer: TOYOTA (Genuine OEM part)
• Part Number: 90105-08100
• Type: Hex flange bolt
• Thread Diameter: M8 (nominal diameter based on Toyota part numbering standards)
• Material: High-tensile hardened steel alloy
• Surface Treatment: Corrosion-resistant zinc-plated or phosphated protective coating against environmental factors and rust
• Design: Integrated flange eliminating the need for a separate washer and reducing the risk of loosening

Function and Importance:

In automotive engineering, flange bolts are utilized in critical assemblies subjected to continuous vibration, temperature fluctuations, and mechanical stress (such as mounting suspension components, engine mounts, exhaust systems, or body panels). The integrated flange expands the load-bearing surface area, delivering a more stable joint while protecting the surface of fastened components from galling or damage during torquing.

Signs of Wear and Failure:

Although genuine Toyota bolts are engineered for exceptional durability, replacement is mandatory in the following circumstances:

• Thread Damage or Elongation: Over-torquing beyond specified tightening limits can stretch or strip the threads, compromising fastener clamping integrity.
• Corrosion and Rusting: Prolonged exposure to moisture and road de-icing salts after coating damage can degrade the bolt's metallurgical strength.
• Fatigue Failure: Sustained vibration and dynamic load cycling can induce micro-fractures, eventually causing the bolt head to shear.

For safe and durable repairs, fasteners that have been loosened or removed—especially on critical suspension and engine assemblies—should always be replaced with new genuine Toyota bolts and torqued to the manufacturer's specified values.