FastenMaster 4 In. HD Timberlok Structure Screws, 50 Pc are designed for heavy-duty applications requiring strong, reliable fastening. These screws feature a countersinking head style and are heat-treated to provide increased strength and durability. Their heavy-duty threads deliver excellent holding power, making them i for driving directly through pressure-treated beams without the need for pre-drilling. For optimal performance, use a 1/2" high torque, low RPM power drill. Included with the screws is a 5/16" hex drive bit for easy installation. Made from carbon steel with an epoxy-coated black finish, these screws combine strength and corrosion resistance for long-lasting use. Model Number: FMTLOK04-50