RJSPHH Trailer Greaseable Spring Bolts 9/16 x 3 (14pcs) — Knurled Shoulder, Grease Zerk for Double-Eye & Slipper Springs

RJSPHH Trailer Axle Greaseable Spring Bolt 9/16 x 3 is a knurled, grease-zerk equipped mounting bolt designed to lubricate and secure double-eye or slipper springs on most common trailer axles.

These 14 bolts (9/16" x 3") are built for trailer suspension points where periodic lubrication keeps movement smooth and reduces wear. Each bolt features a knurled shoulder to stop rotation in the hanger bracket, an integral grease zerk for easy servicing, and a lock nut to maintain clamping force. Compatible with many popular axle ratings, these bolts simplify maintenance and extend the life of spring hangers and equalizers.

Which trailer axles and springs work with these greaseable bolts?

These bolts are compatible with many common trailer axle ratings and spring types used on light- to medium-duty trailers. They suit double-eye and slipper springs when mounted to hanger brackets or equalizers, installing as a direct replacement in most setups that accept a 9/16" x 3" bolt.

• Fits axles typically rated 2000#, 3500#, 5200#, 6000#, 7000#
• Designed for double-eye and slipper style springs
• Standard M12-1.75 thread pitch for wide compatibility
• Knurled shoulder prevents bolt from spinning during installation

How does the grease zerk improve maintenance?

The built-in grease zerk lets you apply lubricant without disassembly, making routine service faster and more effective. Regular greasing reduces friction between the spring and hanger, helping prevent premature wear and noisy operation.

• Grease zerk located in the bolt end for direct lubrication
• Enables on-trailer greasing with a standard grease gun
• Reduces need to remove bolts for service, saving time
• Promotes smoother pivoting and longer component life

What are the bolt’s key construction and safety features?

Each bolt is machined with a knurled shoulder to lock into the hanger and a matching lock nut to secure the assembly. The M12 thread and 0.5625" outside diameter ensure strong clamping force and straightforward replacement of worn or non-serviceable hardware.

• 0.5625" outside diameter, M12-1.75 thread
• Knurled shoulder prevents bolt rotation in the hanger bracket
• Includes grease zerk and lock nut with each bolt
• Drilled and tapped end for grease fittings standard on trailer axles

How should I install and care for these greaseable spring bolts?

Installation follows standard spring hanger procedures: position the spring eye, insert the knurled shoulder bolt so it seats in the hanger, and tighten the lock nut to the vehicle manufacturer's torque specification. Periodic greasing through the zerk keeps the joint operating smoothly; inspect hardware regularly for wear or corrosion.

• Seat knurled shoulder fully into hanger to prevent rotation
• Tighten lock nut to manufacturer torque specifications
• Lubricate through zerk at regular service intervals
• Inspect for wear, replace if threads or knurling are damaged

Who is this for: RJSPHH's 9/16" x 3" greaseable spring bolts are aimed at trailer owners, fleet managers, and maintenance technicians who need a reliable, serviceable fastener for trailer suspension points. If you maintain light- to medium-duty trailers with double-eye or slipper springs and want an easier way to keep suspension pivots lubricated and secure, this 14-piece kit provides ready-to-install, service-friendly hardware backed by a one-year warranty and customer support for any issues.