Self-tapping and construction screws are fasteners with a drilling or threading tip that do not require pre-drilling or thread cutting. Roofing: with an EPDM washer (sealing the hole), a wrench or hex head, painted in RAL color. For corrugated metal and metal tiles. For wood: sharp tip, large pitch, for frame construction. For metal: drill-point (TEK), fine pitch. For drywall: phosphated, Phillips cross slot. Material: C1018/C1022 carbon steel, hardened. Coating: zinc, phosphate, polymer painting (RAL). Sizes: 3.5–6.3 mm × 19–200 mm. Packaging: boxes of 200–1000 pcs. The EPDM washer seals the hole from rain and snow. The service life of the EPDM washer is 25+ years. Head painting: powder, RAL to match the roofing color (3005, 6005, 8017 — popular). For wooden battens: sharp tip. For metal purlins: drill-point (TEK). Packaging: boxes of 250 pcs with a bit included.