These heavy duty rod ends are ideal for today's flexible suspension systems. Super strong, Creeper Joints will hold up to years of punishment. The outer shell is a single forged piece. The inner flex ball is made from 8620 tool steel and rides on high quality polyurethane bushings. Heavy-duty, hardened steel washers hold the joint together. Creeper Joints are super flexible and allow for up to 40 degrees of movement when used with spacers. A threaded grease fitting is provided on top for lubrication. The flex ball is drilled for cross lubrication flow from the shell to the link mount bolt. Each joint includes a jam nut! Three different flex ball sizes; 9/16", 5/8" & 18mm, allow you to choose the right size to match your application. The threaded section is 1-1/4" in diameter with 12 threads per inch. Creeper Joints are also available in a shackle mount for use with leaf springs. Using a Creeper Joint on the shackle end of a leaf spring reduces spring binding and increases suspension flex. Creeper Joint shackle mounts are sold in pairs and do not include the shackles, bolts or spring bushings.