When you’re building something that’s meant to last—whether it’s a timber frame, a gate, or a heavy-duty door—you need hardware that holds its own. That’s where the coach bolt, also known as a carriage bolt, comes into play.

It’s simple, solid, and time-tested. And at Old West Iron, we carry them in styles that nod to both tradition and strength.

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What Is a Coach Bolt?

A coach bolt—or carriage bolt, depending on where you hang your hat—is a type of bolt with a smooth, domed head and a square shoulder just beneath it. That square section is designed to grip into the wood or metal being fastened, preventing the bolt from spinning while you tighten the nut on the other end.

Key features:

• Rounded head: Clean look, no sharp edges, sits flush to surface

• Square neck: Locks into material to prevent rotation

• Threaded shank: For securing with a washer and nut

They’re most commonly driven into pre-drilled holes and tightened from the nut side. Because the head has no tool grip (like a hex or slot), they’re tamper-resistant and visually clean—ideal for applications where appearance matters.

Why Are They Called "Coach" or "Carriage" Bolts?

The name goes back to the 18th and 19th centuries, when these bolts were commonly used in the construction of horse-drawn coaches and wagons. Their flush, rounded heads didn’t snag on reins, cargo, or clothing, making them ideal for fastening wooden wheels, panels, and framework.

In America, the term "carriage bolt" stuck. Across the pond in the UK, they’re still widely referred to as "coach bolts." Either way, it’s the same reliable fastener—and it’s been doing the job for centuries.

Where to Use Coach Bolts Today

• Timber framing & post-and-beam construction

• Rustic or industrial furniture

• Gates, barn doors, and fences

• Pergolas, porches, and pavilions

• Anywhere you want a low-profile head and solid connection

Coach bolts aren’t just for looks—they offer true mechanical strength, making them ideal for both structural and decorative applications.

Finishes That Match Your Build

At Old West Iron, our carriage bolts come in a variety of finishes to complement any design style:

• Raw or waxed steel for a natural, aged appearance

• Black powder coat for a classic colonial or Gothic look

• Oil-rubbed bronze for warm, antique charm

• Zinc or stainless options for high-exposure or marine use

And because we focus on heritage hardware, we carry decorative bolt heads that mimic traditional hand-forged styles—ideal for restoration work or period-inspired builds.

Tips for Installation

• Pre-drill your hole slightly larger than the square shoulder if working with hardwoods

• Use a rubber mallet or wooden block to tap the bolt in place without damaging the head

• Tighten from the nut side with a washer to distribute pressure

• Consider pairing with decorative clavos or square nuts for extra style

Finish with the Right Fastener

A build is only as good as the hardware that holds it together. Whether you’re restoring an old barn door or crafting a modern structure with traditional soul, coach bolts provide strength you can count on—and a finish that belongs in the story.

Browse Our Full Collection of Carriage Bolts »

Maddison Mellem
Writing from the forge at Old West Iron