Durock 1-1/4" Screws (600 count), $24.99 USD/Box, LL Flooring (Lumber Liquidators)

Durock screws are quality, corrosion-resistant fasteners designed for attaching backerboards and underlayments to wood or steel frames. They are suitable for both interior and exterior uses and feature a coating that passes extensive salt-spray tests. Dual drive design ensures easier driving and longer bit life, while the large wafer head provides strong holding power. Designed with strip-out prevention ribs, different thread designs cater to specific framing needs and color contrast for visibility. Packaged in a clear, durable jar including a compatible bit, the screws are ideal for varying installation sizes.