1、Heat Treatment: Made of heat treated steel, the bolts have a strong oxide film on the surface, which enhances their anti wear and erosion quality and prolongs their service life. 2、High Strength: Bolts with 18 threads per inch, deep and clear. Heat treated bolt has a higher strength and hardness, anti tensile and torsion, not easy to deform or break under high loads. 3、Application: These trailer leaf spring shackle bolts are used to fix your leaf springs to the leaf spring hangers and also to the center equalizer bar of the trailer. 4、Wide Compatibility: The leaf spring shackle bolt set is suitable for use with trailers that have 2,000lb and 3,500lb axles, versatile use with wide compatibility. 5、Package Include: You will receive 4pcs leaf spring shackle bolt with matching lock nuts, providing a complete solution for your trailer attachment needs.