The Simpson Strong-Tie ATRM 1-1/8 in. x 24 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. Its fully threaded profile also makes it well-suited for use as an adhesive anchor rod and a wide range of other structural anchoring applications.

Key Features

• Precut 24 in. length - ready to install straight out of the package, eliminating on-site cutting and saving time during structural assembly.
• Meets Grade 55 specifications (ASTM A36; Fy = 55 ksi and Fu = 75 ksi) - delivers the tensile and yield strength required for demanding seismic and wind-force load path applications.
• UNC Class 2A thread specification - ensures consistent, reliable thread engagement with compatible nuts, couplers, and hardware components used in continuous rod tiedown systems.
• 1-1/8 in. rod diameter - provides substantial cross-sectional area to handle high tension loads in shearwall overturning restraint and roof uplift restraint systems.
• Uncoated black steel finish - suited for interior structural applications where a coating is not required, keeping material costs straightforward without unnecessary surface treatment.
• Fully threaded (all-thread) along entire length - allows connectors, couplers, and nuts to be positioned anywhere along the rod, maximizing installation flexibility across a variety of structural configurations.

Why This Product

• Designed specifically as a tension transfer element for seismic and wind-force resistance, this rod addresses the critical need for a continuous, uninterrupted load path from roof to foundation in shearwall and uplift restraint systems.
• The fully threaded design means hardware engagement is not limited to specific points on the rod, giving structural installers the flexibility needed to accommodate varying stud bay depths and connection heights without compromise.
• With Grade 55 mechanical properties (Fy = 55 ksi and Fu = 75 ksi) and UNC Class 2A threads, this rod meets established structural specifications, supporting confidence in engineering compliance for permitted construction projects.
• Beyond tiedown systems, the all-thread rod profile makes this rod usable as an adhesive anchor rod, giving builders and contractors a versatile fastening solution that works across multiple application types on a single jobsite.

Specifications

• Brand: Simpson Strong-Tie
• MPN: ATRM9-2
• Product Class: Threaded Rod
• Rod Diameter: 1-1/8 in.
• Rod Length: 24 in.
• Material: Uncoated Steel
• Finish: Uncoated Steel
• Color: Black
• Thread Specification: UNC Class 2A
• Grade: Grade 55
• Standard: ASTM A36
• Yield Strength (Fy): 55 ksi
• Ultimate Tensile Strength (Fu): 75 ksi
• Quantity: 1
• Country of Origin: United States
• Prop 65: No

Approved Applications

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

Frequently Asked Questions

What structural systems is the Simpson Strong-Tie ATRM9-2 designed for?

The ATRM9-2 is designed as a tension transfer element for structural systems built to resist seismic and wind forces. It can be used within a continuous rod tiedown system for shearwall overturning restraint, in an uplift restraint system for roofs, and as an adhesive anchor rod, providing a continuous and reliable load path from roof to foundation.

What are the thread specifications for the ATRM9-2 all-thread rod?

The ATRM9-2 features a UNC Class 2A thread specification. This standardized thread form ensures reliable compatibility with nuts, couplers, and other hardware components used throughout continuous rod tiedown system assemblies.

What are the mechanical strength properties of this threaded rod?

The ATRM9-2 meets Grade 55 specifications per ASTM A36, with a yield strength (Fy) of 55 ksi and an ultimate tensile strength (Fu) of 75 ksi. These properties make the rod suitable for demanding structural tension applications involving seismic and wind-force load transfer.

Is the ATRM9-2 supplied precut, or does it require field cutting?

The ATRM9-2 comes precut to a length of 24 in. with a diameter of 1-1/8 in., so no field cutting is required for this size. The precut format is intended for installation convenience, allowing the rod to be used directly in compatible tiedown and uplift restraint system configurations.