Type 18-8 are standard grade, while 316 is a superior type often referred to as marine-grade steel. It’s known for its durability against harsh conditions that cause rust or corrosion. While 18-8 and 316 stainless steel bolts have a similar strength composition, restaurants, hospitals, and water treatment facilities are best served by marine-grade products.
Not sure about Home Depot, but the Hillman products at our Ace store are listed as 18-8.
What's 304 listed as? I just snagged a box of them too.
Found it. Ok I feel good about using these.
IS 304 STAINLESS STEEL A GOOD CHOICE FOR MARINE ENVIRONMENTS?
Clinton offers SAE 304 stainless steel, which can also be found under the name A2 stainless steel or 18/8 stainless steel. 304 is the most popular stainless steel alloy available on the market. It is an austenite steel, meaning that it is non-magnetic in nature. This alloy was first developed by Firth Brown Steels nearly a century ago. It was originally sold under the trademark Staybrite 18/8, because of the presence of chromium (at around 18%) and nickel (around 8%) as alloying agents.
304 steel has a eutectoid point that occurs at 727 °C (1,341 °F). While it is not a good choice for applications that require electrical or thermal conductivity, it is well known for its excellent formability. With a carbon maximum of .03 percent, this alloy is also ideal for welding operations under 800 degrees F. While heat treatment is not an option, cold working can be performed to make the material both harder and stronger.