Hillman 5/16 in. x 3 in. Zinc-Plated Steel Carriage Bolt, 100-Pack
Regular price $40.995/16 in. x 3 in. Zinc Carriage Bolts (100-Pack)
Zinc-plated steel carriage bolts designed for fastening wood to wood or metal while providing a smooth, low-profile dome head finish. The square shoulder locks into the material to prevent spinning during tightening, delivering a clean, secure install for decks, fences, carts, and general projects.
Key Features:
- Zinc-Plated Protection: Resists rust and corrosion for durable indoor and light outdoor use
- Low-Profile Dome Head: Creates a smooth, snag-free surface ideal where clearance is limited
- Square Shoulder Lock: Grips the material to prevent bolt rotation—no washer needed under the head
- Multi-Material Use: Fastens wood to wood or wood to metal with reliable holding power
- Installation Tip: Pre-drill a hole matching the bolt diameter for best results
Specifications Table:
| Specification | Details |
|---|---|
| Bolt Diameter | 5/16 in. |
| Length | 3 in. |
| Thread Size | 5/16-18 UNC |
| Material | Steel |
| Finish | Zinc-plated |
| Head Type | Dome (carriage) head |
| Shoulder | Square shoulder under head |
| Pack Quantity | 100 pieces |
| Intended Use | Fasten wood to wood or wood to metal |
| Installation Recommendation | Pre-drill hole matching bolt diameter |
Frequently Asked Questions (FAQ):
Q: What materials can these carriage bolts fasten?
A: They are designed to fasten a wood face to either wood or metal.
Q: Do I need a washer under the head?
A: No— the square shoulder seats in the material to prevent turning, eliminating the need for a washer under the head.
Q: Are these suitable for outdoor use?
A: The zinc plating offers moderate corrosion resistance, suitable for indoor and some light outdoor applications; for harsh environments, consider stainless or hot-dip galvanized.
Q: What drill size should I use?
A: Pre-drill a hole that matches the bolt diameter (5/16 in.) for proper fit.
Q: What nuts are compatible?
A: Use 5/16 in.-18 coarse thread nuts and washers as needed on the nut side.
A Clean, Domed Detail for Seamless Strength
The soft dome of this carriage bolt delivers a polished, unobtrusive accent—strength that disappears into the design. I love how the square shoulder locks in, keeping the head flush and refined on benches, gates, and utility carts. Pair it with zinc hardware for a cohesive, silvery sparkle that feels both functional and elevated. It’s the quiet essential that makes everyday builds feel luxe and intentional.
Secure your next project with these zinc-plated carriage bolts—order the 100-pack and build with strength and a clean, low-profile finish.
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