Prime-Line 9056389 Hex Lag Screws, 3/8 in. X 4 in., Grade 18-8 Stainless Steel, 15-Pack
Brand: PRIME-LINE
Size: 3/8 inch X 4 inch
Heavy duty wood screw with 6 sided hex bolt head
Features deep wood screw threads and does not accept a nut
Used in applications where standard wood screws cannot support the load (deck building, etc.)
Requires pilot hole to be drilled and installs using wrench or socket tool