Anchor Bolts vs. Anchor Rods: What’s the Difference and When to Use Each

When planning a structural or infrastructure project, terms like anchor bolts vs anchor rods often get used interchangeably. But are they really the same thing? If you’re involved in specifying fasteners for foundations, sign posts, precast concrete panels, or steel columns, understanding the difference can help you avoid confusion — and ensure you’re getting the right product for the job.

In this blog, we’ll clarify the terminology, compare technical differences, and explain when to use each option.

Anchor bolts are threaded fasteners used to secure structural components to concrete. Typically, they have a head or bent end that gets embedded into poured concrete. Once cured, the threaded portion protrudes from the concrete and connects to base plates, columns, or equipment with nuts and washers.

• L-Bolts (90° bent bolts)
• J-Bolts
• Headed anchor bolts (with forged hex or heavy hex head)
• Sleeve anchor bolts or expansion anchors (for retrofit use)

Anchor bolts are often defined by shape, head type, and concrete embedment. They are commonly manufactured to ASTM F1554 Grades 36, 55, and 105.

Anchor rods are straight threaded steel rods used as anchoring elements in concrete foundations. Unlike anchor bolts, anchor rods may not have a head or bend — they are typically threaded on both ends and used with nuts and washers on both sides (embedded + exposed).

They are often used in situations where:

• The foundation is precast and the rod must be inserted after casting
• A steel base plate requires full-thread adjustability
• Multiple levels of anchoring and leveling are required

Anchor rods are also commonly manufactured to ASTM F1554 or A193 B7 standards, and may be supplied with or without a plate or nut tack-welded on the embedded end.

Feature	Anchor Bolt	Anchor Rod
Shape	Bent (L/J) or headed	Straight, fully or partially threaded
Concrete Embedment	Often cast-in during pour	Cast-in or installed into precast sleeves
Ends	One embedded end, one threaded	Usually threaded on both ends
Typical Use	Traffic poles, signs, foundations	Precast panels, industrial bases, modular steel structures
Common Standards	ASTM F1554, A307	ASTM F1554, A193 B7, ISO 898-1

Use anchor bolts when:

✅ You are pouring a new concrete foundation from scratch

✅ A bent or headed bolt can be embedded for solid anchorage

✅ You’re installing traffic signal poles, sign posts, or equipment bases

✅ The project references DOT specs or ASTM F1554 Grade 55 with bend requirements

These are ideal for cast-in-place concrete foundations, where anchoring is permanent and the bolt head or bend offers mechanical pull-out resistance.

Use anchor rods when:

✅ You’re working with precast concrete foundations or base sleeves

✅ You need threaded adjustment on both ends

✅ The connection requires field alignment flexibility

✅ You’re bolting down large steel columns, base plates, or structural supports

✅ The spec calls for A193 B7 rods or high-strength threaded assemblies

Anchor rods are ideal for modular assembly, field-retrofitting, and applications requiring easy installation and removal.

Even experienced professionals may use “anchor bolts” to refer to both types — especially in conversation. Some engineers use “anchor rods” for any structural anchoring system, while others differentiate strictly by shape and installation method.

When in doubt:

👉 Check the project specifications

👉 Confirm the required standard (ASTM F1554, A193, etc.)

👉 Clarify the end-use: poured vs. precast, adjustable vs. fixed

Anchor bolts and anchor rods serve a similar purpose — anchoring structural elements to concrete — but their differences matter when it comes to design, installation, and long-term performance. Choosing the right one for your application can reduce installation errors, improve safety, and ensure compliance with project specifications.

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Need help determining which anchoring system fits your project?

At TUHU Fasteners & Manufacturing Inc., we supply a wide range of anchor bolts and anchor rods that meet ASTM and ISO standards — with technical support to help you get it right.

👉 Browse Our Anchor Bolt & Rod Products

📧 Or contact us at sales@tuhufasteners.com for a fast, expert response.