The conventional slotted head is most effective made use of with a flat screwdriver, while the cross-shaped indention is ideal suited to your Phillips screwdriver. A Robertson screw provides a sq.-formed indention and needs a matching driver head. You can not use a pozi driver over a Philips drive screw, https://wood43075.sharebyblog.com/28429983/the-basic-principles-of-wood-screws