TYPES OF SCREW HEADS NO FURTHER A MYSTERY

A slotted screwdriver is still accustomed to travel just one of several two perpendicular slots found in the fastener head of the cross or double-slot screw drive. This kind is usually present in roofing bolts as well as other similarly priced items that have a thread which is at least 5 mm (0. Phillips head screwdrivers appear in a number of meas