What is Threaded Rod? FAQ & More
Threaded rod is one of those unsung heroes of construction and fabrication: simple, strong, and endlessly useful. If you've worked on a building site, fabricated a frame, or suspended piping, chances are you’ve used it. And if you haven’t, you probably should.
At Fasteners Plus, we offer a wide selection of threaded rods in multiple materials, lengths, and strength grades, ready to ship for jobs of any size. This guide covers the essentials, plus the most common questions customers ask about this indispensable fastener.
What is Threaded Rod?
Threaded rod, sometimes called all-thread or redi-rod, is a long, straight bar made of metal, most commonly steel, that is threaded across its entire length. This uniform threading allows it to be used with nuts and washers from both ends, enabling applications that bolts simply can’t match in reach or versatility.
It’s used extensively in construction, mechanical installations, electrical mounting, concrete anchoring, and even cabinetry and home repair projects. If you need to fasten, suspend, or secure something, there’s probably a threaded rod for that.
What’s the Difference Between Threaded Rod and Bolts?
The key difference lies in design and application. A bolt has a head and can be partially or fully threaded, designed for fastening components with torque. Threaded rod is headless and fully threaded, offering continuous fastening or anchoring through materials of various thicknesses or at long spans.
| Feature | Threaded Rod | Bolt |
|---|---|---|
| Head | None | Yes |
| Threading | Full length | Partial |
| Use Case | Suspension, anchoring | Clamp two items |
| Length | Customizable | Fixed |
When Should You Use Threaded Rod Instead of a Bolt?
Use threaded rod when you need extended reach, structural anchoring, or high tension. Some common examples include:
- Suspending HVAC ductwork or piping from ceilings
- Securing structures into concrete floors
- Running fasteners through multiple objects of varying thickness
Whereas, using bolts is great for:
- Joining two pieces of metal or wood with high clamping force
- Fastening into tapped holes, such as machinery frames or engine blocks
- Assembly lines or equipment installs, where a wrench or impact driver needs a bolt head for grip
- Bracket mounting or beam connections, where the bolt shank resists movement better than threaded rod
What Are Other Names for Threaded Rod?
You may hear different names depending on your region or trade. Other common names include:
- All-thread
- Redi-rod
- Threaded bar
- Threaded stud
- Continuously threaded rod
These different terms usually describe the same product, but they hint at what the rod is built for. For example, "all-thread" highlights that the rod is threaded from one end to the other, while "redi-rod" emphasizes that it is ready to cut, install, and use without special preparation. No matter what name you hear, the function remains the same: continuous threading for flexible fastening solutions.
What Types of Threaded Rod Are There?
The best threaded rod depends entirely on where and how you plan to use it. Different environments and load requirements call for different materials and strength grades. Here's a breakdown to help guide your selection:
Types of Threaded Rod Materials:
- Zinc-Plated Steel: Great for indoor and dry applications
- Hot-Dip Galvanized: Extra corrosion resistance for outdoor use
- 304/316 Stainless Steel: High corrosion resistance for marine or harsh environments
Types of Threaded Rod by Thread Type:
- UNC (Coarse) – Most common in general construction
- UNF (Fine) – More precise threading
- Metric – Standard in international projects
Types of Threaded Rod by Strength Grade:
- A307: General-purpose carbon steel
- B7: Heat-treated, high-strength alloy steel for structural/tension use
-
F1554 Grade 55: Specifically for concrete anchoring
- There are other F1554 Grades, like 36 or 105, that are less common
What is the Best Threaded Rod?
Choosing the best threaded rod comes down to understanding the environment and load demands of your project. Not every job requires the strongest or most expensive option, but it should always match the job site conditions and expectations for long-term performance. Here's how different types stack up based on common applications:
- Most Suited for Outdoors: Hot-dip galvanized or stainless steel
- Most Suited for Structural Use: ASTM B7 or F1554 Grade 55
- Most Suited for Budget Projects: A307 plain or zinc-plated
Additional FAQs About Threaded Rod
Can Threaded Rod Be Used Outdoors?
Absolutely, but only if it’s made from corrosion-resistant materials like stainless steel or hot-dip galvanized steel. Standard zinc-plated rods may rust if exposed to moisture over time.
How Do You Anchor Threaded Rod in Concrete?
Anchoring threaded rod in concrete is a common practice across construction, electrical, and mechanical trades. The goal is to create a secure connection that can hold up under tension, shear, or vibration, depending on the application. There are a few proven methods to get the job done, each with its own benefits and use cases:
- Epoxy anchoring - chemical adhesive
- Expansion anchors - wedge or sleeve types
- Mechanical couplers - for joining rods in-line
Do You Need Nuts and Washers with Threaded Rod?
Yes. In most cases, a nuts and washers (flat or lock) are used with threaded rod to secure objects from both ends and ensure stability under vibration or load.
Conclusions About Threaded Rod
Threaded rod is a fastener that belongs in every pro’s and DIYer’s toolkit. It’s simple, adaptable, and capable of securing everything from ceiling-mounted HVAC systems to heavy-duty structural columns.
