Available in two sizes this useful tool positions over the pin and then using leverage you wind down the pin until it meets the waher on top of the joint disc. Use a little bit of extra pull to tighten the pin well to ensure a secure fit!

Another tip that is worth mentioning is to make sure that you have no creases between the joint discs as these will loosen the joint once you start moving the arm or leg. I also like to trim away any pile between the discs to ensure a nice snug fit!

Tha small key is for the little joints 7mm - 12mm.

The medium black handled key for all cotter pins joints from 15mm. Which use the medium or latge cotter pin sizes.