Timco 3.9 x 16mm Window Fabrication Screws Countersunk 121Z (Box of 1000)

Effortless Fastening into Reinforced Frames

Modern PVCu window frames rely on internal steel or aluminium reinforcements for structural integrity. However, attaching hardware to these metal cores can be time-consuming if you have to pre-drill every single hole. The TIMCO 121Z fabrication screw solves this bottleneck entirely. Outfitted with a highly effective self-drilling point, this screw acts as its own drill bit. It effortlessly pierces through the PVCu outer layer and drills directly into metal reinforcements up to 2.5mm thick, securing locks, keeps, and hinges in a fraction of the time.

The Advantage of Under-Head Ribs

When installing window hardware, the screw head must sit perfectly flush. If a screw protrudes, it can catch on moving parts or prevent the window from closing correctly. To combat this, TIMCO has integrated specialized milling ribs underneath the countersunk head. As the screw is driven home, these ribs carve out a neat, precise recess in the plastic or metal frame. This guarantees that the screw head pulls down completely flush every single time, without causing the surrounding plastic profile to bulge or crack under the pressure.

Reliable TIMCO Quality

Manufactured from high-strength carbon steel, these self-drilling screws are built to handle the rigorous torque of impact drivers and high-speed fabrication tools. They are finished in a bright zinc coating, giving them a Corrosion Rating of 2. This makes them highly resilient for use in the sheltered, occasionally damp environments typical of window rebates. Packaged in a robust box of 1000 pieces, they provide the consistent quality and volume that professional fabricators demand.