This is the most common screw style, it is used for general interior work and has the widest range of sizes 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.
If you can't see the right size here make sure to check the zinc-plated countersunk screws as well.
Origin of the Robertson square drive screws
The "Robertson" screws were invented in Canada by Peter Robertson in 1908. Due to patent restrictions they stayed in Canada for many years and became the standard screw in that country. They are now spreading rapidly through the US and other countries. It is a far superior system and we are sure you will agree “once you use them you don't want to use anything else”.
Not only is the drive system better than the conventional drives, the actual quality of the screws is superb. The screws are extremely strong and the square drive means the driver doesn't jump out and the screw does not break under heavy load.