Lag Bolt vs. Structural Screw

Structural screws were engineered to replace lag bolts in many connections. The choice usually comes down to code approval, speed, and cost.

FeatureLag BoltStructural Screw
Pilot hole neededYes (avoids splitting wood)Usually no (self-drilling tip)
Shear strengthGoodHigher per diameter
Installation speedSlower (drill then drive)Fast with an impact driver
Code acceptanceLong history, universally acceptedVia ICC-ES evaluation reports
CostCheaper per piecePricier per piece

Verdict

For new structural work, structural screws are faster and stronger, but always check the evaluation report. Lag bolts remain a proven, cheaper choice where speed does not matter.

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