1、Wide Compatibility: This spring screw is drilled out with a grease zerk on the end, suitable for most trailer axles including 2000lb, 3500lb, 5200lb, 6000lb and 7000lb Axles, catering various needs. 2、High Strength Steel Material: The spring shackle screw is made of high strength steel material, resistant to oxidation, deformation and wear, ensuring long lasting use. 3、Practical Use: Keep trailer suspensions lubricated with the greaseable spring screw for mounting double eye or slipper style axle springs to hanger brackets or equalizers. 4、Enhanced Stability: Knurled shoulder of this trailer axle shackle prevents screw from rotating in the hanger bracket, including grease zerk and lock nut, providing excellent stability and reliability. 5、Improved Performance: The greasable spring shackle screw can maintain and prolong the life of your trailer suspensions, enhancing the overall performance of your trailer.