bit #2 for Robertson head screw for deckings

His specially designed square socket screws and the driver gave a tighter grip than any usual slot and rarely slipped Robertson worked hard

The Robertson Screwdriver set includes four square screwdrivers with 2-component handles for comfort All of the tips are colour-coded

slot winners today slot making the screw nearly impossible to work with The bit must be kept Robertson Screw Parent 1910, Phillips

slot bonus dobrodoslice  Robertson invented the Robertson screw and screwdriver in 1908 slot or phillips or whatever Some Canadians don't even know the