MEGAFastener Dura-Screws - Zinc Plated Case Hardened Steel Phillips Pan Head Self Drilling Sheet Metal Dura-Screws. Pan head screws have a flat bottom, rounded sides and a slightly flattened top. They are used in a variety of applications where a flat bottomed head screw is desired to sit on top the surface of the materia. Thread Type: Self Drilling Sheet Metal Dura-Screws. These super-handy self-drilling screws were designed to fasten and secure two pieces of material (metal-to-metal or metal-to-wood, metal-to-plastic, etc) together, without the need for pre-drilling).