What are Nuts
Nuts, essential pieces of climbing equipment, are wedge- or hexentric-shaped pieces of metal, generally made of lightweight aluminum, that are snugly placed or slotted in cracks. Nuts provide protection for a lead climber, who clips into the nut with a carabiner or quickdraw, and as a belay anchor.
Nuts Come in Different Shapes and Sizes
Nuts, made in various sizes and shapes to accommodate many crack sizes and widths, are an important climbing tool since they do not damage the rock with repeated insertion and removal as pitons, which are hammered into and out of cracks, damage the rock surface, leaving unsightly piton scars.
First Nuts Used in England
The first climbing nuts used were actual machine nuts for bolts that were picked up along railroad tracks in England beginning in the 1950s and then threaded with a thin cord to clip a carabiner to the nut. Some types of nuts are Hexentrics and Stoppers, both made by Black Diamond, a climbing equipment manufacturer in Salt Lake City, Utah.