Metal pegboard systems are usually made out of steel. Metal pegboards are usually mounted in strips, as it would be comparatively costly, cumbersome and inefficient to sell in larger sheets. Sufficiently thick metal pegboards will not sag between mounting points. Instead, the system's mounting on surfaces such as wood beams or sheetrock will usually fail under a heavy weight before the metal pegboard does. Manufacturers advise customers to hang tools and other gear based on the estimated strength of the mounting points. High quality metal pegboard systems use extruded holes, while other systems have the holes drilled after casting.