M2W SD Roof Screw. Power Pro metal-to-wood self drilling roofing screws are designed to fasten steel roofing to wood purlins used in post-frame wood construction & plywood or OSB used in residential construction. These screws feature 2.5 mils of powder coating with a chromate sealer, offering 3x the corrosion resistance of painted heads. The under-head V-neck design adds strength and prevents head popping. EPDM rubber is vulcanized to a steel washer to form an excellent seal even when driven at an angle. The threading on these screws transitions from fine to coarse in order to generate superior holding power in various wood substrates. The Micro-Bit point design reduces metal shavings that can otherwise embed themselves in the rubber washer. This feature helps the screw start fast and finish straight when driven. Size 10 x 1.50. Size 1 lb.