Specifically designed for joining of PVCu bay window sections, but frequently used for other window and door fabrication purposes. Fire Classification: A1" Thread Dia. mm: 4.8 Length mm: 60 Head Type: Wafer Flange Recess Type: Phillips Thread Type: Self-Tapping V Flute Point Type: Self-Drilling Finish: Zinc Material: Carbon SteelSize 4.8 x 60 - 200 Pieces Timco Baypole Screws - Wafer Flange - PH - Self-Drilling Point - Zinc in Silver