Nuts & Hexes
Nuts are tapered aluminium wedges set on a loop of strong stainless steel cable, and form the backbone of a trad climbing rack. They are slotted into cracks in the rock at a constriction, where they will provide secure protection if placed correctly. The larger sizes usually have a curved shape that gives a stable 3-point placement and can sit around lumps and irregularities in the crack. Smaller sizes (micro-nuts) are usually made from a brass or bronze alloy, silver-soldered directly onto the cable. Nuts with an offset taper are also useful in flaring cracks or old piton scars.
Hexes (or hexcentrics) are larger nuts with an eccentric hexagon shape that will twist and cam into parallel cracks. Tricky to place and have largely been superseded by spring-loaded camming devices, but they still have their uses, particularly in winter climbing where they'll bite into iced up cracks.
