These SPAX screws are manufactured from Grade 5 Hardened Steel, have an unslotted Hex Washer Head, and are available with a high corrosion resistant coating (HCR). No pre-drilling is required in most materials. They will not break. SPAX screws are an instant solution for almost any construction project. Great for exterior applications such as decks, playgrounds, fences, landsdcapes, patios, and much more.