Offen called a lag screw. Hex lag bolts are for fastening in wood, Availiable in Carbon Steel; Professional, High Quality
Article: Hex Lag Bolt

Size:1/4''x1''---3/4''x16''

Standard: ANSI

Material: Carbon Steel

Suface&Grade:Grade 2. Zinc plated low carbon steel. Best for general hardware use where high strength is not required;

Cr+3/+6,has a bright mirror-like finish providing sharp looks for a variety of applications

Packing: Bulk/Small Packing/As your request in color and logos, All no problem