How to Assemble a Hammerlock

Hammerlock is used as a chain extender on trailer chains, and when it hangs down, its space in the middle is larger than the original tow bar of the vehicle. Therefore, it is easier and more comfortable to connect shackles or hooks.

  1. Gather your materials: You will need the two coupling link body halves, a tube, a load pin, and a punch. Make sure all the components are clean and free of any damage or defects.
  2. Bring the two coupling link body halves together, position the tube in the center of the hammerlock. 
  3. Insert the load pin through the hammerlock. The load pin should fit snugly into the hammerlock, with no gaps or wiggle room.
  4. Drive the load pin with the punch until the end of the pin is shown with the surface of forging. Use a hammer or mallet to drive the punch into the load pin, pushing it all the way through the coupling link body. The end of the load pin should be flush with the surface of the forging, indicating that it's fully seated.
  5. Check your work: Once the load pin is fully seated, inspect the hammerlock for any signs of damage or defects. Check that all components are properly aligned and seated, and that there are no gaps or spaces between them.


  1. Add some oil to the middle bush every 3 months, or when you find it difficult to hammer in during installation. Normal oil is fine to keep it moist and prevent rust, which can extend the product's lifespan.
  2. When assembling, please do not reverse the two coupling links. They should be connected to each other as shown in the picture.

By following these steps, you can safely and effectively assemble a hammerlock. Remember to always follow proper lifting and rigging protocols, and to never exceed the rated capacity of any component or system.

🛒 Hammerlock + Safety Hook

🛒 Hammerlock + Eye Hook

🛒 Hammerlock + Slip Hook

🛒 Hammerlock + D Shackle