DIN7504K hex flange self drilling roofing screw assembled with bonded EPDM sealing washer. Made of hardened carbon steel. The drill point enables self-drilling into metal purlin without pre-drilling. Integrated EPDM washer provides excellent waterproof, UV & ozone resistance, prevents water leakage on metal roof and wall cladding. Widely used for color steel tile, metal roofing, sandwich panel installation. Sizes ST4.2~ST6.3, length 19–150mm. Zinc plated / color coated / Ruspert finish optional.