5/16"-18 × 2‑1/2" Carriage Bolt – Grade 8, Plain Finish

Built for applications that require extended fastening length and high mechanical strength, the 5/16"-18 × 2‑1/2" Grade 8 carriage bolt offers dependable performance in demanding assemblies. The rounded head provides a smooth, finished surface, while the square neck is designed to lock into wood or metal to prevent rotation during tightening. Manufactured from heat‑treated alloy steel, this Grade 8 fastener delivers high tensile strength suitable for structural and load‑bearing use. The plain, uncoated finish is ideal for controlled environments or installations where coatings are unnecessary. Commonly used in machinery frames, equipment mounts, fixtures, and structural connections requiring secure, long‑reach fastening.