Activities The Great Outdoors All About Spring-Loaded Camming Devices Cams are Essential Rock Climbing Gear Share PINTEREST Email Print Bring a rack of different-sized camming devices along with a set of nuts for a great day of climbing at Turkey Rock. (Stewart M. Green) The Great Outdoors Climbing Gear Basics Health & Safety Highest Mountains Hiking Skiing Snowboarding Surfing Paddling Fishing Sailing Scuba Diving & Snorkeling Learn More By Stewart Green Stewart M. Green is a lifelong climber from Colorado who has written more than 20 books about hiking and rock climbing. our editorial process Stewart Green Updated November 26, 2017 Spring-loaded camming devices (SLCDs), usually called cams, are essential pieces of climbing equipment that are used for climbing protection. Cams, the workhorses of your rack of climbing equipment, form a safety net for your traditional climbing adventures. Camming devices are used to protect a lead climber as he climbs upward and for belay anchors. Cams Revolutionized Climbing Spring-loaded camming devices are the modern safety net for traditional or trad climbing. Before the invention of SLCDs, climbers protected themselves by hammering pitons into cracks and then later they protected routes with various types of nuts which were wedged into cracks. In the late 1970s, climber Ray Jardine revolutionized the sport with the invention of the "Friend," the first camming device. Suddenly, parallel-sided cracks at places like Indian Creek in Utah, which until then were not protectable with climbing gear, opened to climbers. Cams are Mechanical Devices A cam is a specialized mechanical device that expands and retracts to fit inside cracks of any size, giving secure protection and belay anchors to leaders and belayers. Using a trigger, which is pulled down with the fingers, the cam retracts to a smaller size, allowing it to be placed inside a crack. When the trigger is released, the lobes of the cam expand to wedge and fit inside the crack. Cams Adapt to the Rock Cams are popular because they are quick and easy to place in cracks, adapt to variations in the rock surface, and they offer lots of security for leaders and belayers. A well-placed cam will almost never pull out of a crack when it is loaded as in a leader fall. Camming devices are easier to use than monolithic passive protection like nuts, including Hexentric nuts, Stopper nuts, and RPs, for example, if you are jamming a crack up a steep wall and getting pumped. As you climb the crack, you find a secure hand jam and then whip a SLCD off your gear sling or harness gear loop. You place it in the crack, clip the rope to it and, whew!, you’re safe. Lots of Types of Cams are Available Lots of types and brands of SLCDs are available at your local climbing shop so the choice of cams is sometimes bewildering. There are rigid-stem cams and flexible-stem cams; huge cams for fat off-width cracks; link cams which fit lots of different crack sizes; and three-cam units or TCUs for protecting thin finger cracks. Which SLCDs You Should Buy Which SLCDs should you buy for your rack? That's a tough question because cams are expensive and a big investment for a novice climber. If you’re starting out, buy a basic set of standard cams like Wild Country Friends or Black Diamond C4 Camalots. These complement a set of nuts like Stoppers and will protect almost every moderate route that you will climb. Later, as you grow as a climber, you can also expand your rack and buy specialized cams like a #4 Camalot for off-width cracks and a set of TCUs for thin cracks. Your Basic Trad Gear Rack has all the beta on the essential equipment you need to safely lead and protect traditional climbing routes.