Definition of lag screw in English:

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lag screw

Entry from US English dictionary


A heavy wood screw with a square or hexagonal head. Also called coach screw, lag bolt.
Example sentences
  • The wooden mailbox pictured at right, purchased at a Bay Area nursery, is mounted atop a 6-foot-tall 4-by - 4 redwood post and secured with a 3-inch-long lag screw.
  • Then drill these holes on the band and joists, again using a drill bit one size smaller than the shank of the lag screw.
  • To help keep rain water running down the wall from flowing into the structure through the lag screw holes, squirt some silicone caulk in the holes before screwing in the lag screws.


[with object] (lag-screw)
Fasten with a lag screw.
Example sentences
  • The lag-screwed connection failed at less than 200 pounds when the lags pulled out of the band joist.
  • He also designed some brackets that were lag-screwed to the top and bottom of the ridge rafters.
  • But lag-screwed cleats are MUCH more likely to fail as they rely solely on two screws holding into the wood.

For editors and proofreaders

Syllabification: lag screw

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