Sizes 2,3,4,5, and 7 of Ed Leepers Z-nuts. I believe there were 7 sizes of these offered, 1 thru 7. Ed Leeper debuted these new in late 1978/early 1979. They were an interesting idea but had a few drawbacks.
- The nuts had to be slung with thin cord which limited there strength.
- They were designed to be used with a “soft catch” or even with a non-mechanical belay to keep them from deforming under load.
- The design was only truly effective when used in their narrow aspect.
Although not mentioned in magazines or reviews of the time period, I think the Z-nut design suffered by arriving too late. By the 1980s passive climbing protection was starting to sort itself out and climbers were discovering what basic shapes were versatile and trustworthy. Nuts, Stoppers, Foxheads, Rocks, and others were consolidating into forms we would instantly recognize today. Z-nuts might have found a small following if they had come along earlier in the era when climbers were still nailing at times and would have had a hammer to “seat” the Z-nut into difficult placements. I still believe they we flawed but at least they would have had a chance for some merit to be found.
I have only seen one Leeper Z-nut placed anywhere. In the early 1990s there was a medium size Z-nut “fixed” in an old blown out bolt hole on the first pitch of the Colorado Northeast Ridge on Kingfisher Tower, Fisher Towers Utah. It was pounded in nose first like a piton and was buried in mud and crust. Only a ratty piece of frayed 1/2 inch webbing stuck out of the hole. Moving onto that time bomb placement felt like waiting for a punch in the face… You knew it was coming, and it was going to suck!