The regular slotted head is greatest applied with a flat screwdriver, although the cross-formed indention is most effective suited to some Phillips screwdriver. A Robertson screw incorporates a sq.-formed indention and requires a matching driver head. Elevator bolts are used in a wide array of purposes. These bolts can, for https://screws10741.ttblogs.com/8245670/5-simple-statements-about-wood-screws-explained