Prime Line Products 9056560 Lag Screw Bolt, Hex Head, 3/8 in X 6 in, Zinc Plated Steel, Pack of 15

Diameter & Length: 3/8 inch X 6 inch Wood screw with a 6-sided hex bolt head Much thicker than standard wood screws Used in applications where standard wood screws cannot support the load, excellent for deck building where you can not use nuts Requires pilot hole to be drilled and installs using wrench or socket tool, Manufacturer: Prime-Line