A Square Bit Is A System Used To Turn A Screw. At A Minimum It Is A Set Of Shaped Cavities And Protrusions On The Screw Head That Allows Torque To Be Applied To It. Usually It Also Involves A Mating Tool; Such As A Screwdriver That Is Used To Turn It. The Nr 1 Size Bit Is Suitable For Use With Screw Sizes Of 2.8mm 3.5mm
