5/16"-18 × 3" Carriage Bolt – Grade 8, Plain Finish

Designed for long‑reach fastening in high‑strength applications, the 5/16"-18 × 3" Grade 8 carriage bolt provides dependable performance in demanding structural and industrial assemblies. The smooth, rounded head delivers a clean finished appearance, while the square neck is engineered to embed into wood or metal to prevent rotation during tightening. Manufactured from heat‑treated alloy steel, this Grade 8 fastener offers high tensile strength suitable for load‑bearing and high‑stress use. The plain, uncoated finish is ideal for controlled environments or applications where surface coatings are not required. Commonly used in machinery frames, equipment mounts, fixtures, and structural connections requiring secure, extended‑length fastening.