5/16"‑18 Grade 5 Hex Jam Nut – Coarse Thread, Zinc CR+3 Finish

The 5/16"‑18 hex jam nut is manufactured from Grade 5 carbon steel to deliver reliable strength and durability for general‑purpose fastening applications. Featuring a coarse 18‑TPI thread and a thin jam‑nut profile, it is designed for use as a locking nut against a standard hex nut or in space‑restricted assemblies to help resist loosening under vibration. Finished with a Zinc CR+3 coating for enhanced corrosion resistance, this jam nut is ideal for machinery, automotive, maintenance, and industrial applications requiring secure locking and dependable performance.