The normal slotted head is most effective utilized by using a flat screwdriver, though the cross-shaped indention is finest suited to a Phillips screwdriver. A Robertson screw includes a sq.-formed indention and demands a matching driver head. The length of such screws differs, but most drywall screws have flat heads https://rylanstspm.verybigblog.com/28192007/5-tips-about-wood-screws-you-can-use-today