GRK brand R4 PHEinox multi-purpose screws. Handy Pak contains 100 screws, each 5/16 x 6. UPC on package reads 772691 322357.
PHEinox
screws are stainless steel screws that are still reasonably priced.
They can be used in almost any application, and offer a variety of
alternative sizes and screw heads to accommodate.
The
multi-purpose screw has specially designed cutting pockets to maximize
the countersink hole and to move the dust away from the hole. They can
be used in most applications, including wood, plastic, sheet metal,
composite decking and particle board.