The Simpson Strong-Tie ATRM 1-1/8 in. x 18 in. All-Thread Rod, Grade 55 is a fully threaded steel rod engineered as a tension transfer element for structural systems designed to resist seismic and wind forces. Built to provide a continuous and reliable load path from roof to foundation, this all-thread rod is a critical component in continuous rod tiedown systems for shearwall overturning restraint and in uplift restraint systems for roofs - giving builders and engineers confidence that lateral and uplift loads are properly transferred throughout a structure. Its versatility extends beyond tiedown assemblies, making it equally suitable as an adhesive anchor rod in a wide range of construction applications.

Key Features

• Precut 18 in. length - arrives ready to install, saving layout and cutting time on the jobsite
• Grade 55 specification (ASTM A36; Fy = 55 ksi and Fu = 75 ksi) - delivers the medium-strength tensile and yield performance required for structural tiedown and wind/seismic restraint applications
• UNC Class 2A thread specification - ensures consistent, standardized thread fit with compatible nuts, couplers, and bearing plates used in Strong-Rod tiedown systems
• 1-1/8 in. rod diameter - sized to handle significant tension loads in shearwall overturning and roof uplift restraint scenarios
• Uncoated black steel finish - provides a clean, bare steel surface well suited for interior structural applications and adhesive anchor installations where coatings could interfere with bonding
• Fully threaded along the entire length - allows flexible positioning of nuts and hardware anywhere along the rod, simplifying installation and adjustment within the load path assembly
• Made in the United States - manufactured domestically to meet the quality and consistency standards expected in engineered structural systems

Why This Product

• Engineered for continuous load path systems - the ATRM is specifically designed as a tension transfer element, meaning it is built to carry real seismic and wind forces reliably from roof to foundation, not just a generic threaded rod repurposed for structural use
• Dual-system compatibility - works within both continuous rod tiedown systems for shearwall overturning restraint and uplift restraint systems for roofs, reducing the number of different rod types a contractor needs to source and stock
• Adhesive anchor versatility - the uncoated steel surface and UNC Class 2A threading make this rod a practical choice for adhesive anchor applications as well, extending its usefulness beyond dedicated tiedown assemblies
• Predictable structural performance - Grade 55 classification with published Fy = 55 ksi and Fu = 75 ksi values gives engineers and inspectors clearly defined mechanical properties for load calculations and code compliance documentation

Specifications

• Brand: Simpson Strong-Tie
• MPN: ATRM9-1.5
• Product Class: Threaded Rod
• Rod Diameter: 1-1/8 in.
• Rod Length: 18 in.
• Grade: Grade 55
• Thread Specification: UNC Class 2A
• Material Standard: ASTM A36; Fy = 55 ksi and Fu = 75 ksi
• Material: Uncoated Steel
• Finish: Uncoated Steel
• Color: Black
• Quantity: 1
• Country of Origin: United States
• Prop 65: No

Approved Applications

• Continuous rod tiedown systems for shearwall overturning restraint
• Uplift restraint systems for roof applications
• Adhesive anchor rod installations
• Structural systems designed to resist seismic forces
• Structural systems designed to resist wind forces

Frequently Asked Questions

What structural systems is the ATRM9-1.5 designed to work within?

The ATRM9-1.5 is designed for use as a tension transfer element in structural systems that resist seismic and wind forces. It is specifically suited for continuous rod tiedown systems providing shearwall overturning restraint and for uplift restraint systems used in roof applications. It can also be used as an adhesive anchor rod in other construction applications.

What are the mechanical strength properties of this all-thread rod?

The ATRM9-1.5 meets Grade 55 specifications per ASTM A36, with a minimum yield strength (Fy) of 55 ksi and a minimum tensile strength (Fu) of 75 ksi. The threading conforms to UNC Class 2A standards for reliable compatibility with structural hardware used in load path assemblies.

Is this rod coated or treated for corrosion resistance?

No - this rod is made from uncoated black steel with no surface coating applied. This makes it appropriate for interior structural applications and for use as an adhesive anchor rod where a bare, uncoated steel surface is needed for proper bonding.

Does the ATRM9-1.5 come precut or does it need to be cut to length on site?

The ATRM9-1.5 comes precut to 18 in. in length, so no field cutting is required for this specific size. The fully threaded design allows nuts and hardware to be positioned anywhere along the rod during installation.