The conventional slotted head is best employed by using a flat screwdriver, when the cross-formed indention is most effective suited to the Phillips screwdriver. A Robertson screw has a square-shaped indention and requires a matching driver head. This bolt, combined with the machine screw that goes with it, sits on https://wood-screws31964.blue-blogs.com/34863118/an-unbiased-view-of-screws