How and where to use guide
A400401STB Ulti-mate II Professional Woodscrew PoziSquare Double Csk BZP&Y - (8g) 4mm X 40mm - 200
Typical applications
These screws are ideal for general woodworking, joinery, and construction tasks where reliable fastening is required. The 40mm length makes them suitable for fixing sheet materials to timber frames, attaching hardware, and general assembly work across both hardwood and softwood projects.
- Fixing plywood, MDF, chipboard and OSB to timber frames
- Attaching sheet metal components to timber
- General joinery and construction assembly
- Cabinet making and furniture assembly
- Securing fixings and hardware to timber substrates
Installation and driving technique
The Stick-Fit connection between the screw and included driver bit allows the fastener to remain engaged without manual support. Position your workpiece with one hand whilst driving the screw with the other, ensuring the bit remains fully engaged in the PSD recess throughout insertion. Drive at a steady speed to maintain control and prevent cam-out. The double countersunk head sits flush with the surface when fully driven, suitable for applications where a neat finish is required.
- Ensure the driver bit is fully engaged in the PSD recess before driving
- Use one hand to position the workpiece and the other to drive
- Maintain steady driving speed to prevent bit slip
- Drive until the countersunk head sits flush with the surface
- Pre-drilling is recommended in hardwoods to prevent splitting
Material compatibility and limitations
These screws perform well across a broad range of materials including softwoods, hardwoods, and engineered timber boards. The BZP&Y finish provides adequate corrosion resistance for internal use and protected external applications. However, for fully exposed external use in harsh environments, stainless steel fasteners may offer superior longevity. Avoid use in applications subject to sustained moisture exposure without additional protective measures.
- Suitable for hardwood, softwood, MDF, plywood, chipboard and OSB
- BZP&Y finish appropriate for internal and protected external use
- Pre-drilling recommended in dense hardwoods
- Not recommended for fully exposed wet environments without protection
On-site storage and handling
Store screws in a dry environment to maintain the integrity of the BZP&Y finish. Keep the included Stick-Fit driver bit in good condition and replace if the tip becomes damaged or worn, as a compromised bit will not maintain proper engagement with the PSD recess. The box of 200 provides sufficient quantity for most standard projects whilst remaining portable on site.
- Store in dry conditions to prevent corrosion of the finish
- Inspect the driver bit regularly for wear or damage
- Replace the driver bit if it no longer engages securely in the screw recess
- Keep the box sealed when not in use to protect remaining fasteners