The conventional slotted head is most effective used with a flat screwdriver, whilst the cross-shaped indention is very best suited to a Phillips screwdriver. A Robertson screw features a square-shaped indention and demands a matching driver head. Thread forming screws are much like thread chopping screws, but as opposed to https://erickttttq.is-blog.com/34607726/the-basic-principles-of-wood-screws