Someone, a few days ago,brought up the Swinden key. They said that the Swinden key was used in a lot of knives, including the Imperial KampKing. When i was a boy, my knife was a KampKing. The blade deveoped a lot of play because i used the knife very hard . One day i was bearing down,atempting to press the cutting edge through a tree branch. The blade actually squeezed backward between the spring and liner causing the blade to pivot over backward (folded over backward). I was aghast,as this was my one and only knife. I managed to pop the blade back into it's proper position. Blade play fom hell, up and down and side to side. Feeling that the knife was ruined and that i couldn't hurt it worse than i already had, i put the bolster in a vise and tweaked the knife, pulled it and checked it. I continued slightly tweaking (slightly pinching the bolster) again and again. After doing this VERY slowly and methodically, i sucessfully took most of the blade play away. I was able to use the knife for 3 or four more years. I still have it (that was forty years ago) it still works. Hope you understand my explaination, hope it helps. SLOW AND EASY TWEAK AND TEST. regards Henry