The Simpson 1/2 in. x 5 in. Zinc-Plated Retrofit Bolt from Simpson is a precut threaded rod supplied with a nut and washer, engineered to work with anchoring adhesives to anchor into existing concrete and masonry. Each end of the threaded rod is stamped with the rod length in inches and color-coded to indicate the grade or type of steel, allowing for quick and easy identification post-installation. For 1/2 in. diameters and larger, the distinctive No-Equal symbol is also stamped on each end. When paired with a compatible Simpson Strong-Tie adhesive, the RFB delivers a complete engineered anchoring system built for demanding structural connections.

Key Features

• Handles both tension and shear loads - supports a wide range of structural connection demands in a single fastener, reducing the need for multiple anchor types.
• Coarse thread type - promotes strong mechanical engagement with adhesive for reliable, consistent anchoring performance in concrete and masonry.
• Zinc-plated finish - provides a corrosion-resistant surface that helps extend service life in typical installation environments.
• End-stamped with rod length and color-coded by steel grade - makes post-installation inspection and verification fast and straightforward without guesswork.
• No-Equal symbol stamped on each end (1/2 in. diameter and larger) - gives installers and inspectors an additional layer of quick visual confirmation on the job site.
• Supplied with nut and washer included - arrives ready to use as part of a complete anchoring assembly, streamlining installation prep.

Why This Product

• A complete engineered anchoring system in one package - when combined with a Simpson Strong-Tie adhesive, this retrofit bolt provides a fully integrated solution for anchoring into existing concrete and masonry, giving contractors confidence in the overall system performance rather than relying on mixed components.
• Dual load capacity built in - the ability to carry both tension and shear loads means this threaded rod anchor is versatile enough to handle a broad range of structural connection scenarios without needing a separate fastener for each load type.
• Simplified post-installation verification - the color-coded ends, stamped rod length, and No-Equal symbol allow inspectors and installers to confirm the correct bolt is in place quickly, reducing errors and saving time during inspection.
• American-made quality from a trusted structural brand - produced domestically and backed by Simpson Strong-Tie engineering, this retrofit bolt is a dependable choice for professionals who need a proven threaded rod anchor for retrofit and new anchoring applications alike.

Specifications

• MPN: RFB#4X5
• Brand: Simpson Strong-Tie
• Diameter: 1/2 in.
• Bolt Length: 5 in.
• Thread Type: Coarse
• Grade: Grade 36
• Coating: Zinc Plated
• Finish: Zinc Plated
• Country of Origin: United States

Approved Applications

• Anchoring into existing concrete using Simpson Strong-Tie adhesives
• Anchoring into existing masonry using Simpson Strong-Tie adhesives
• Structural connections requiring both tension and shear load resistance

What's Included

Each pack contains (1) RFB#4X5 Retrofit Bolt, Precut threaded rod (1/2 in. x 5 in.), Nut, Washer.

Downloads and Resources

• Model No. RFB#4X5 Coating/Material. Zinc Plated Size (in.) 1/2 x 5 See Specifications

Frequently Asked Questions

What adhesive should be used with the Simpson RFB#4X5 Retrofit Bolt?

The RFB#4X5 is designed to be used with Simpson Strong-Tie adhesives to anchor into existing concrete and masonry. When paired with a compatible Simpson Strong-Tie adhesive, it provides a complete engineered anchoring system.

How can the RFB#4X5 be identified after installation?

Each end of the threaded rod is stamped with the rod length in inches and is color-coded to indicate the grade or type of steel, allowing for quick and easy identification post-installation. For 1/2 in. diameters and larger, the distinctive No-Equal symbol is also stamped on each end.

What types of loads does the RFB#4X5 Retrofit Bolt support?

The RFB#4X5 provides both tension and shear loads in connections, making it suitable for a wide range of structural anchoring applications in existing concrete and masonry.

Does the RFB#4X5 come with a nut and washer?

Yes. The Simpson RFB#4X5 is supplied with both a nut and a washer, providing all the components needed for installation alongside a compatible Simpson Strong-Tie anchoring adhesive.

Note: Product dimensions and/or length may differ from picture. Please see the item description above for specifications.