What are window fabrication screws?
They're self-tapping screws made for building and repairing uPVC windows and doors. The point and thread cut into plastic frames, letting you fix hardware like hinges, locks and handles without pre-drilling a threaded hole.
What does a high-low thread mean?
A high-low thread alternates a tall thread with a shorter one between it. The taller thread digs deep into soft uPVC for grip, while the low thread adds holding power. Together they resist the screw working loose over time.
Can I use these where the frame has no steel reinforcement?
Yes. That's exactly what they're for. They bite into the plastic itself, so they hold hardware securely in frames where there's no steel or aluminium reinforcement behind the face.
What drive do they take?
A Phillips (PH) recess. Match your driver bit to the screw size for a firm fit and to avoid chewing out the head.
What size screws should I use for uPVC windows?
Pick a length that reaches through the hardware plate and into the frame wall without punching out the far side. These come in a range of window-trade lengths, so check the product options and match to your job.
Are these screws corrosion resistant?
The zinc plating gives good corrosion resistance for interior fabrication and repair work on windows and doors.