Ice climbing requires a full kit of equipment not used for rock climbing, from crampons to ice screws. Screws are one of the most important pieces of gear an ice climber owns. Every ice climber knows that a dull screw creates frustration and can slow climbing down. Screws dull over time from use and can be damaged from contacting rock under ice. A number of brands make screws, including Petzl, Black Diamond, DMM and Grivel.