TIMCO Wing Tip Self Drilling Screw for Heavy Section Steel - 5.5 x 45mm - Pack of 200

Good screws, be very helpful if spec on website included max thickness that can be fixed down with screw length I needed to fix 18mm board to steel I thought 45mm screw would be ample but the drilling section and the bit with the snap off clearance wing take up 25 mm and the 20mm left includes the counter sunk head. Got over it by counter sinking the board first bit more time consuming which could have been avoided if the information was on the specification as would have bought longer screws