The quick change die holder system on my power hammers has worked very well for years. After I got the rhythm of using them worked out I rarely dropped a keeper during a die exchange. However, there was one with one problem. The drop pin which locks the key in place is tethered to the key and the tethers have a tendency to break.
The first tethers were long leather strips. However if a hot work piece contacted the leather it would burn through it. Later I tried a heavy nylon cord and that worked even less well for the same reason. The current tethers are steel chain. They have worked so well I think they may be the end of the story.
|Keeper Key and pin in locking position.|
|Keeper key and pin in storage position.|