Simpson #9 x 2" Metal-Panel Screw with EPDM Washer, 316 Stainless SteelModel No. T09200HWA Coating Material. Type 316 Stainless Steel Screw Size. #9 Length (in.) 2 Head Diameter (in.) 0. 630 Drive Type. 1 4 in. Hex Head Type. Hex Head Thread Type. Twin Threads Point Type. Sharp Point The metal panel screw with EPDM washer is designed to fasten aluminum agricultural siding panels to wood joists without predrilling. To withstand the most corrosive environments, these screws are Type 316 stainless steel. Applications