The normal slotted head is greatest utilized having a flat screwdriver, whilst the cross-shaped indention is most effective suited to the Phillips screwdriver. A Robertson screw incorporates a sq.-shaped indention and needs a matching driver head. The length of those screws may differ, but most drywall screws have flat heads https://screws29741.blogocial.com/5-essential-elements-for-screws-64594355