Stainless Steel Carriage Bolts
What are stainless steel carriage bolts? Stainless steel carriage bolts are round, domed-head bolts with a square neck under the head that bites into wood to stop the bolt spinning as the nut is tightened. Made from stainless, they resist rust in decks, docks, and outdoor wood while leaving a smooth, tamper-resistant head on the show side.
Why stainless carriage bolts last outdoors
Carriage bolts spend their life in wood that gets wet, and modern pressure-treated lumber is corrosive to ordinary hardware. Stainless resists both the moisture and the treated-wood chemicals that rust plated bolts and streak the wood around the head. For docks, waterfront, and coastal builds, step up to 316 for the best resistance to salt and pitting. Match your nuts and washers to the same grade so the whole connection stays corrosion resistant.
Why choose stainless steel carriage bolts
- Smooth, safe head: rounded profile reduces snags and protects surfaces.
- One-side installation: the square neck locks into wood so you tighten from the nut side.
- Corrosion resistance: holds up in wet, treated, and coastal wood.
- Grade options: 18-8 for general use, 316 for salt and chloride exposure.
Common applications for stainless carriage bolts
- Decks, docks, fences, and pergolas
- Playground and park equipment where snag-free heads matter
- Trailer wood floors and tie-downs
- Timber framing and general carpentry (use 316 for coastal)
Pair these with matching square nuts or hex nuts and fender washers to spread load in wood. Browse every material on the main carriage bolts category.
Stainless Steel Carriage Bolts FAQ
Do stainless carriage bolts work in pressure-treated wood?
Yes, and they are the better choice. Treated lumber corrodes plated bolts, while stainless resists the chemical attack and avoids rust streaks in the wood.
How do I install a carriage bolt so it does not spin?
Drill a snug round hole and tap the bolt so the square neck seats into the wood. As you tighten the nut, the neck grips and stops the bolt from turning.
Should I use 18-8 or 316 carriage bolts?
18-8 suits most outdoor wood. For docks, saltwater, and coastal exposure, choose 316 for the best corrosion resistance.