Hex Bolt vs. Carriage Bolt
Both join parts with a nut, but they are built for different jobs. A hex bolt is tightened from the head; a carriage bolt is tightened only from the nut side.
| Feature | Hex Bolt | Carriage Bolt |
|---|---|---|
| Head | Six-sided (external wrench) | Smooth domed head |
| How it is tightened | Head or nut side | Nut side only |
| Anti-turn feature | None (wrench holds it) | Square neck bites into wood |
| Typical strength | Up to Grade 8 | Usually Grade A or Grade 5 |
| Best for | Metal-to-metal, machinery | Wood-to-wood, exposed surfaces |
Verdict
Choose a hex bolt for strength and general assembly. Choose a carriage bolt for wood connections where you want a smooth, snag-free head and one-wrench installation.