Multiple uses for fitting a variety of hardware to frames where there is a steel or aluminium reinforcement present. Thread Dia. mm: 3.9 Length mm: 38 Head Type: Countersunk Recess Type: Phillips Thread Type: Self-Tapping Point Type: Self-Drilling Finish: Zinc & Yellow Material: Carbon SteelSize 3.9 x 38 - 1000 Pieces Timco Window Fabrication Screws - Countersunk - PH - Self-Tapping in Yellow