CAMO 5/16-in x 4-in Black Epoxy Flat-Head Exterior Structural Wood Screws (250-Pack) in the Lag Screws department at Lowes.com
Grip-Rite 5/16 in. x 6 in. Structural Screw Dual Drive/Hex Washer Head (50-Piece/Pack) GRSSHW516650 - The Home Depot
Carpenters Mate® TX30 Flat Head Structural Timber Screws 6.5 x 200mm 200pk
15x4" Black Wafer Head Structural Lag Screws. Used for Log Construction, Timber Framing, Laminated Beams and Pole Barns Among Other Uses. T-30 Torx/Star Drive
Dril-Flex Structural Drill Screws, Undercut Flat Phillips Head
Starborn Structural F23 Multi-Purpose Flat Head Wood Screw - Pack of 250-2-7/8": Amazon.com: Industrial & Scientific
5/16 x 4" GRK RSS™ Flat Head Climatek™ Finish T-30 Drive Steel Structural Wood Screw | Fastenal
Flat Head Ledger Structural Screw By CAMO - DecksDirect