Hex Head Lag Screws
Hot Dipped Galvanized Steel
Hot Dipped Galvanized finish offers corrosion resistance to steel fasteners due to the molten zinc bath finishing process, creating a bonded alloy coating. Hot dip galvanizing is a process that adds a layer of corrosion resistance by dipping fabricated steel into a kettle containing molten zinc. The HDG process creates a tightly bonded alloy for superior corrosion resistance and harsh environment applications. HDG products must be used exclusively when applied, meaning that a plain zinc nut or stainless nut cannot be applied to an HDG bolt. HDG nuts are threaded slightly larger than other nuts to make room for the thickness of the galvanized coating.
Lag bolts, also called lag screws, are basically "large wood screws". A typical lag bolt is a 6 inches long, 3/8 diameter screw with coarse threads of a wood-screw or sheet-metal-screw threadform (but larger). The head is typically an external hex. The materials are stainless steel for corrosion resistance. Lag bolts are used to lag together lumber framing, to lag machinery feet to wood floors, and other heavy carpentry applications. These fasteners are clearly "screws" when defined by the Machinery's Handbook distinction. The term "lag bolt" has been replaced by "lag screw" in the Machinery's Handbook. However, in the minds of most tradesmen, they are "bolts", simply because they are large, with external-hex heads. In the United Kingdom, lag bolts/screws are known as coach screws.