Timber Fixing Screws. Single Part Thread Hardened Screw. Specifically used in decking construction. Properties Length: 200mm. Width: 7mm. Insert bit size: 8mm. Head: hex flange. Finish: anti-corrosion green treated. Application: deck construction. Quantity: box of 50. Features • Extremely coarse thread offering increased holding power in all types of decking timber. • ACQ resistant exterior grade coating with up to 1000 hours salt spray protection. • Also widely used in exterior timber, fencing and landscaping applications. • Magnetic nut setter included for speed of installation.