Maxi-Loc screws are the Kreg Screw of choice for the majority of applications. These screws have a large head that provides maximum bearing surface as the screw pulls tight in the pocket. Blue-Kote finished screws feature three anti-corrosion layers, making them the ideal choice for a wide variety of indoor and outdoor projects. Rust-resistant screws, works with pressure treated material. Recommended for use with softwoods, as well as for sheet goods such as plywood and MDF that are soft and not very dense. The deep aggressive threads bite into soft fibers to ensure solid holding power.