5/16"-18 × 2‑1/4" Grade 8 Indented Hex Flange Screw – Zinc Yellow CR+6, Baked (Non‑Serrated)

Engineered for heavy‑duty structural and automotive applications, the 5/16"-18 × 2‑1/4" coarse‑thread Grade 8 indented hex flange screw is commonly specified for frame and chassis assemblies. The integrated non‑serrated flange distributes clamping force evenly while protecting mating surfaces, eliminating the need for a separate washer. Manufactured from high‑strength alloy steel, this fastener is finished with zinc yellow CR+6 plating to enhance corrosion resistance. A post‑plating bake process helps reduce the risk of hydrogen embrittlement, ensuring dependable performance in high‑stress environments.