These screws are similar to steel countersunk screws but with four lugs under the head so the screw doesn't crack the surface of the board or veneers. Also, becuse of the lugs, rather than spinning the head in the material it grips the smooth board and pulls it down under the surface making it a neat and effective screwing solution.
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.
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.