FlatLOK is a multi-purpose structural wood screw that can be used for fastening multi-ply LVL and girder trusses. The flat head allows for easy finishing including drywall or trim.

FlatLOK is approved for single-sided installation making the job easier to complete both at ground level or for elevated applications.

The FlatLOK wood screw features a TORX® ttap® drive system that maximizes bit fit, reducing the potential for stripping. The stability button allows for maximum penetration into the fastener and a wobble-free drive. A free TORX ttap bit is included in every box.


  • 2 7/8”: 2-ply roof girder trusses and 2-ply dimensional wood headers
  • 3 1/2″: 2-ply LVL beams
  • 4”: Interior corridor ledgers
  • 4 1/2”: 3-ply roof girder trusses and 3-ply beams
  • 5”: 3-ply LVL beams
  • 6″: 4-ply roof girder trusses and 2-ply open web floor trusses
  • 6 3/4″: 4-ply LVL beams

FlatLOK is tested and supported by engineering data that conforms to the most current ICC standards. It is also approved for use in ACQ or treated lumber. For FlatLOK technical information, see the Technical Docs section below. For technical documentation see Fastenmaster’s Technical Resources page.