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B&Q£5.90Visit shop B&Q - Double-Countersunk Yellow-Passivated Carbon Steel Screw (Dia)4.5mm (L)70mmPack Of 100
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This guide is for DIY enthusiasts and builders who need reliable fasteners for wood and plasterboard projects. The Diall Double-Countersunk Screw offers strong carbon steel construction with a yellow zinc plating for moderate corrosion resistance, ideal for general-purpose use. A potential consideration is the need for pre-drilling, especially in harder materials, to prevent splitting.
| Colour | Yellow |
|---|---|
| Brand | Diall |
These screws typically have a cross-head (Phillips) drive. Ensure you use a Phillips head screwdriver or bit that matches the size of the recess to prevent stripping.
No, the yellow zinc plating offers only moderate corrosion resistance and is best suited for indoor applications. For outdoor use, screws with a more robust coating like galvanization or stainless steel are recommended.
A double-countersunk head is designed to sit flush with the surface of the material, providing a neat appearance and reducing the risk of snagging. It also helps to prevent the material from splitting around the head.
Each pack contains 100 screws.
These screws are designed for wood and plasterboard. They are not suitable for directly fastening into metal without appropriate pre-drilling and potential pilot hole preparation.
The screws are constructed from durable carbon steel.
While plasterboard is softer, pre-drilling a pilot hole is still good practice, especially if you are screwing into the plasterboard multiple times or into a stud behind the plasterboard, to ensure a clean insertion and avoid damaging the board.
Ensure you are using the correct screwdriver bit and that it is seated firmly in the screw head. Check that a pilot hole has been drilled correctly and is not obstructing the screw's path.
You have not pre-drilled a pilot hole, or the pilot hole is too small. Use a drill bit suitable for the core diameter of the screw and re-drill the hole before inserting the screw.
Ensure you are using the correct screwdriver bit type (e.g., Phillips) and size. Do not overtighten the screw, as this can damage the head. Apply firm, steady pressure when driving.
Verify that the material thickness is appropriate for the 70mm screw length. Ensure you are screwing into a solid substrate (like a stud or solid wood) and not just thin material. If screwing into plasterboard, ensure it is adequately supported.
Setup: To use these screws effectively, it is recommended to pre-drill a pilot hole, especially when working with timber. The pilot hole diameter should be slightly smaller than the screw's core diameter (excluding the threads) to ensure optimal grip and prevent wood splitting. Use a screwdriver or drill with an appropriate bit to drive the screw. Ensure the screw is driven straight to achieve the flush finish of the double-countersunk head.
Compatibility: These screws are recommended for use on plasterboards and general wood applications. The carbon steel construction and yellow zinc plating are best suited for indoor environments. They are not recommended for exterior use or in areas with high humidity or exposure to corrosive substances.
Care: Store screws in a dry environment to maintain the integrity of the yellow zinc plating and prevent rust. Keep the container closed to avoid contamination.
