You can use the HSS Cobalt spiral drill bit to pre-drill for the recommended
Stainless steel 3.5 x 20 mm screws. It is recommended to pre-drill into certain materials so that the recommended screws can be easily attached in the bead of the gutter and in the
end profile L77. Thanks to the 130-degree tip angle, you cut into metal types of steel with ease. Great for drilling in cast iron and stainless steel. This drill has a diameter of 1 mm.