An ice screw is a hollow, threaded metal tube with a hanger and cutting teeth that a climber screws into solid ice to create a protection point or anchor while ice climbing. Once threaded fully into good ice, an ice screw provides surprisingly strong protection. Placing screws quickly and reading ice quality are core ice-climbing skills, since a screw is only as good as the ice it's in.
A sling (or runner) is a loop of strong webbing or cord, usually sewn closed, that is one of the most versatile pieces of climbing gear. Slings are used to build and extend anchors, reduce rope drag by extending protection, sling natural features like trees and horns, create personal tethers, and improvise rescue systems. They come in various lengths and in nylon or high-strength Dyneema materials.
An ascender is a mechanical device that grips a rope when loaded in one direction and slides freely in the other, allowing a person to ascend a fixed rope. Ascenders come in handled versions (jumars) used in pairs for efficient rope ascension and smaller, compact ascenders used for hauling, progress capture, and rescue systems. They are the mechanical counterpart to friction-hitch knots like the prusik.
A static rope is a low-stretch rope designed to elongate very little under load, making it ideal for applications where stretch is undesirable — rappelling, ascending (jumaring), hauling loads, rescue, and fixed lines. Crucially, a static rope must never be used to catch a lead fall: with little stretch to absorb the energy, it would transmit a dangerous, potentially injurious shock load to the climber and anchor.
A dynamic rope is a climbing rope engineered to stretch under load, absorbing the energy of a fall by gradually decelerating the climber rather than stopping them abruptly. This stretch reduces the peak force on the climber, protection, and anchor, making dynamic ropes essential — and required — for any climbing where falls are caught, including lead and top-rope climbing. Types include single, half, and twin ropes for different applications.
An ATC (Air Traffic Controller) is a tube-style belay device — a simple metal tube through which the rope is threaded and bent over a carabiner to create friction for belaying and rappelling. Lightweight, inexpensive, and versatile (it handles single and double ropes), the ATC relies entirely on the belayer's brake hand for control, with no mechanical braking assist. 'ATC' is a Black Diamond brand name often used generically for tube devices.
A nut (also called a chock or stopper) is a piece of passive, removable climbing protection consisting of a shaped metal wedge on a wire or cord, which the climber slots into a tapering constriction in a crack so that a downward pull wedges it tighter. With no moving parts, nuts are simple, light, inexpensive, and reliable in the right placements, and are a staple of traditional climbing alongside spring-loaded cams.
A cam (spring-loaded camming device, or SLCD) is a piece of removable climbing protection with spring-loaded lobes that retract when a trigger is pulled and expand to grip the walls of a crack when released. Because the lobes convert a downward load into outward pressure against the rock, a well-placed cam holds falls securely while remaining removable, making it the workhorse of modern traditional climbing for parallel-sided cracks.
A dihedral is an inside corner in the rock where two faces meet at an angle, forming a 'V' or open-book shape that the climber climbs from the inside. Climbing a dihedral often relies on opposing pressure — pushing or pulling against both walls (stemming, laybacking, or jamming a corner crack) — rather than positive holds. It's the concave opposite of an arête (an outside corner or edge).
An arête is a sharp, outward-projecting edge of rock. In climbing it refers to a prominent outside corner or rib — the convex opposite of an inside corner (dihedral) — climbed by balancing on and pinching the edge. In mountaineering, an arête is a narrow, knife-edge ridge formed by glacial erosion, often exposed and technical. The term comes from the French for 'fishbone' or 'ridge'.
