How and where to use guide
ST400500 Ulti-mate II Professional Woodscrew PoziSquare Double Csk Z&Y - (8g) 4mm X 50mm - 800 Tub
Typical applications
These screws are ideal for general woodworking, cabinetry, and joinery where a neat countersunk finish is required. The 50mm length suits fastening of hinges, fittings, and hardware to timber frames and components. The absence of ribs on smaller sizes makes them particularly suitable for hinge installation and fitting attachment where a flush, professional appearance is essential. They perform well in softwoods and hardwoods where splitting resistance is a priority.
- Hinge and hardware installation on doors and frames
- Cabinet and furniture assembly
- Joinery and general woodworking
- Fastening of fittings and brackets to timber
Driving and installation
The quick start point allows rapid engagement with minimal force, reducing operator fatigue on high-volume work. The pozisquare recess provides state-of-the-art anti-camout performance, delivering stick-fit and stable driving with either PH or PZ drivers. The reinforced double angle head self countersinks as it drives, eliminating the need for pre-drilling countersink holes in most softwoods. The slotted shank actively reduces wood splitting during insertion.
- Use a PH or PZ driver matched to the recess for optimal engagement
- Apply steady downward pressure to maintain driver contact and prevent camout
- Allow the double angle head to self countersink; do not over-drive
- Pre-drill in hardwoods or near timber edges to minimise splitting
Durability and maintenance
The zinc yellow plating provides reliable corrosion resistance for interior applications and protected exterior use. These screws are engineered to resist breakage during installation thanks to the reinforced head design, reducing waste and rework on site. Once installed, no maintenance is required; the coating protects against rust and discolouration in normal service conditions.
- Zinc yellow plating suits interior and sheltered exterior applications
- Not recommended for direct exposure to salt spray or harsh weather
- Reinforced head design minimises breakage during driving
- Store in dry conditions to preserve coating integrity
On-site tips
The 800-tub packaging is designed for trade use, offering excellent value for high-volume projects. Keep screws dry and organised on site to prevent coating damage and ensure quick access. The self-centering pozisquare recess means less time spent aligning the driver, improving productivity. For hinges and fittings, the rib-free design on these smaller sizes ensures a professional flush finish without visible deformation around the fastening point.
- Store tubs in dry conditions away from damp or corrosive environments
- Use the correct driver size to maximise anti-camout performance and reduce fatigue
- The quick start point means less downward pressure needed to begin driving
- Ideal for high-volume hinge and fitting work where consistency matters