#6 x 10mm (3/8'')..Flat head Csunk Steel screws thread Tapping
This is the most common screw style, it is used for general work and has the widest range of sizes. It is the bread and butter line of screws and allows the screw to be sunk into the timber or fitting for a flat surface.
The standard finish is "Lube" which has a bronze/Grey colour. The colour of the screw comes from the heat treatment after which a dry wax is applied to prevent corrosion and ease driving.
#1 is the driver bit size for #6 gauge screws.