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 and in applications where the screw may come into 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 the tip matches the width of the screw slot otherwise you run the risk of damaging the screw head. Slotted screwdrivers are available with either Flared or Parallel tips. For the majority of uses the Flared tip is ideal but if the screw needs to be driven below the material surface a Parallel tip screwdriver should be used. Countersunk heads are designed to sink flush with substrates to leave a smooth surface finish. The single threads have been designed to offer higher pull out values and quicker insertion.ForgePack of 20 ForgeFix Wood Screws Slotted CSK Brass 3/4in x 8PTDFORFPC348B