The S2500 series metal roof panel is a mechanically seamed structural metal roof system. Designed primarily as a structural metal roof for pre-engineered buildings, this Armco style metal roofing panel is the industry's most extensively tested metal roof system, with over 70 years of history in the field. The S2500 system incorporates a unique heavy-duty interlock clip that secures the metal roof panels while allowing thermal expansion and contraction. This metal roof system is designed with double lock seams.