Lag Bolt vs. Carriage Bolt
Both are staples of wood construction, but they clamp differently: a lag bolt threads into the wood, while a carriage bolt passes through and uses a nut.
| Feature | Lag Bolt | Carriage Bolt |
|---|---|---|
| Fastens into | The wood itself | A nut on the far side |
| Access needed | One side only | Both sides (to place the nut) |
| Hold strength | High pull-out resistance | Through-bolt clamp load |
| Removal | Unscrew | Unscrew the nut |
| Best for | Ledgers, posts, heavy hanging | Decks, fences, through-connections |
Verdict
Use lag bolts when you can only access one side or want to anchor into thick wood. Use carriage bolts for clean through-bolted connections with a smooth exposed head.