These forgefix traditional slotted single thread wood screws have countersunk heads and can be used in many internal and external applications they have a solid brass construction to avoid corrosion application used for both decorative applications and in applications where the screw may come in to contact with the elements avoiding corrosion can be used with all manner of wall plugs slotted screw driver required with slotted screwdrivers it is important to ensure that the tip matches the width