316 Stainless Flat Head Socket Cap Screws

Our flat head socket cap screws in 316SS come in imperial sizes and have a flat head with a wide bearing surface and a countersunk (CSK) head making them ideal for a finished appearance and solid holding power. They are driven with a hex socket drive, also known as an allen drive. A hex key or allen wrench is used to drive them. 

These flat socket cap screws all conform to ASME B18.3. All are fully threaded. Length is measured from the top of the head.

Purchase by the piece, or in large boxes to receive quantity discounts and pricing that will beat any other retailer. Simply enter the quantity you'd like in the "Quantity" box above and your discount will be applied if applicable.

Why is 316 Stainless Steel superior to standard stainless in a marine environment?

Most retailers will sell stainless steel machine screws and not name the alloy. "Stainless Steel" encompasses a large variety of alloys, and you'll often find that an inferior, and cheaper to produce "Stainless Steel" is what's sold when the alloy goes unnamed. We only carry Type 316, passivated Stainless Steel cap screws, and won't sell you anything less, as it's not what we would use on our boat.

316 (A4) Stainless Steel is far more corrosion resistant than it's 304, A2, or 18-8 Stainless Steel counterparts, and should be your go-to alloy in a marine stainless steel application. The additional nickel and molybdenum in 316 stainless as well as the passivation process adds additional corrosion protection that is necessary in a marine or otherwise corrosive environment.

What is stainless steel passivation and how does it help keep our stainless marine fasteners corrosion free?

Stainless steel passivation is a chemical process that improves the corrosion resistance of our 316 stainless fasteners by removing any traces of iron from the surface of fastener. This chemical process enhances it's natural oxide layer, and helps keep any surface rust from forming for years to come.