... for mine tunnel, mine tunnel secondary support, and mountain tunnel support .U25,U29,U36 type steel frame. ... U25/U29/U36 Steel Arch Support for Mining:1.Spec.: 25U, 29U, 36U ... used for mine laneway, mine laneway secondary support, and the support of the mountain tunnel in supporting purposes.Feature of ... one The below is our samples of U steel arches U25/U29/U36 Steel Arch Support for ...