These Phillips flat head zinc wood screws are a #4 x 5/8 in. size, supplied as a box of 100. Zinc wood screws are designed to join two pieces of wood. The smooth shank allows the screw to pull two pieces of wood together for a tight join, while preventing the wood from pulling or splitting. A pilot hole is required for installation. Use them for wood projects around the home such as cabinet, patio or framing assemblies. The screws are tapered along the threading to optimize holding power.