One of the most important steps in placing a rock climbing bolt is cleaning the hole prior to installing the bolt. All dust and debris must be removed. Our steel brushes are made with high quality Carbon Steel and have excellent wear resistance. Carbon Steel is stiffer than our nylon brushes. It wears longer and cleans debris easier than soft brushes. This brush is perfect for manually cleaning bolt holes for glue in bolts. The handle is made of twisted steel wire.