FASTAP PLUS DURACOAT Exterior Self-Drilling Screws have the same features as our interior screws, plus a few additional features. FASTAP PLUS screws have our Duracoat coating which protects against rust and outlasts any galvanizing process years longer in the toughest of environments. FASTAP PLUS screws use a properly heat treated larger wire diameter than most competitors, allowing for greater shear strength and holding power.