Lag Screws

Lag Screws, are sometimes incorrectly called Lag Bolts. They usually have a square or hexagonal head and a wood screw-style thread with a point. Because of their larger diameter, they usually require a pre-drilled hole. They are usually much larger diameter than wood screws, and are used to connect wood or like materials that need to bear a heavy load. In the U.K., Lag Screws are known as Coach Screws.

Lag screws are heavy-duty screws used in woodworking applications. They are designed to support much heavier loads than wood screws or construction screws. They have coarse threads and tapered points that allow them to support a lot of torque. Lag screws can be installed using a wrench or nut driver. The name is misused occasionally these days to refer to square drive wafer head deck screws.
Common applications of Lag Screws are:

  • • Lumber
  • • Heavy Duty Construction
  • • Wooden Playground Equipment
  • • Bridges
  • • Railroads
Lag Screws Diameters

Lag Screws are available on the FCH Network with Imperial/US diameters that range from #1 to 1 1/4 and with Metric diameters that range from M5 to M20. The length of Lag Screws is usually measured from the point to the underside of the head.

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Lag Screws Lengths

Lag Screws are available on the FCH Network with lengths that range from 1/2 to 18.

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Lag Screws Head Types

Lag Screws are available on the FCH Network with head types that range from flat to wafer.

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Lag Screws Drive Types

Lag Screws are available on the FCH Network with drive types that range from phillips to 6-lobe.

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