Jerry McClure

Dagger Bladesmith

"Making knives is like rocket science, but without the rocket." ~ me

The Story Behind my Folders

ruby linersMy idea for the ruby pivot for my folding knives came about in 1998 when I was looking inside a 21 jewel watch. Knowing that watches of this type last a life time, I began to question if this concept could be used in making knives. I thought about using the rubies as a bearing surface for a folding knife. Curious, I talked to a watch maker about my idea. He agreed that the rubies should work just as well in a knife as they do in watches, and without any wear.

I immediately started my prototype by milling cavities into titanium liners and cementing 2.oo mm rubies into the holes, using 8 in each liner for my bearing surface. I then hand-lapped the rubies down until there was a .006 in protruding. I assembled the prototype with 3 micron diamond lapping compound for the final fit. After opening and closing the model over 500 times, I disassembled it to see how my lap pattern looked. After a minor cleaning, it looked immaculate! I reassembled it again and I opening and closed it so see how it felt. It worked like a dream! Smooth like peaches and cream!

I only had one problem: it squeaked as it opened. A touch of knife lube swiftly and easily solved that problem. After some redesign, I came to my present design. Five 3 mm diameter rubies in each liner set in a semicircle. This makes a very large diameter bearing surface area.

The very first knife I made with this system I still use, to this day. It has been 9 years and other than an annual lube job, it still works like a dream and maintains the smoothest operation. I never clean it or take it apart. I use it daily at my job as a mechanic for the National Guard. I use this pivot system exclusively in all of my folders. The wear resistance of the ruby surface dramatically outlasts the conventional bronze and Teflon washers and does not hold in grit.