The Simpson Strong-Tie ATRM 5/8 in. x 18 in. All-Thread Rod, Grade 55 is a fully threaded black steel tension transfer rod engineered for structural systems designed to resist seismic and wind forces. Built to ASTM A36 standards with a minimum yield strength of 55 ksi and a tensile strength of 75 ksi, this rod delivers a continuous and reliable load path from roof to foundation - making it a trusted component in continuous rod tiedown systems, shearwall overturning restraint applications, and uplift restraint systems for roofs. Its UNC Class 2A thread specification and precut 18-inch length also make it well-suited for adhesive anchor rod applications and a wide range of other structural uses.

Key Features

• Precut 18 in. length - ready to install without field cutting, saving time and labor on the job site.
• Grade 55 specification (ASTM A36; Fy = 55 ksi, Fu = 75 ksi) - provides verified medium-strength performance for structural load transfer in seismic and wind-force applications.
• UNC Class 2A thread specification - ensures compatibility with standard nuts, couplers, and other hardware used in continuous rod tiedown and uplift restraint systems.
• 5/8 in. rod diameter - a common structural size that fits within Simpson Strong-Tie anchor tiedown system components designed for shearwall overturning restraint.
• Uncoated black steel finish - a straightforward, no-frills construction suited for interior structural applications where a protective coating is not required.
• Made in the United States - manufactured domestically, supporting consistent quality and reliable availability for structural construction projects.

Why This Product

• Designed specifically as a tension transfer element within Simpson Strong-Tie's Strong-Rod Systems, this threaded rod is engineered to work within a complete, engineered load-path solution for seismic and wind force resistance - not just a generic fastener.
• The precut 18 in. length eliminates the need for on-site cutting and threading, reducing installation time and the risk of field errors in critical structural connections.
• With ASTM A36 material properties and a Grade 55 rating, this rod meets clearly defined, code-relevant strength specifications - giving engineers and contractors a dependable basis for structural calculations.
• Its versatility extends beyond tiedown systems - the all-thread rod design also supports use as an adhesive anchor rod, making it a practical multi-application component for structural and foundation work.

Specifications

• Brand: Simpson Strong-Tie
• MPN: ATRM5-1.5
• Rod Diameter: 5/8 in.
• Rod Length: 18 in.
• Material: Uncoated Steel
• Finish: Uncoated Steel
• Color: Black
• Grade: Grade 55
• Thread Specification: UNC Class 2A
• Material Standard: ASTM A36
• Yield Strength (Fy): 55 ksi
• Tensile Strength (Fu): 75 ksi
• Product Class: Threaded Rod
• 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 applications
• Structural systems designed to resist seismic forces
• Structural systems designed to resist wind forces

Frequently Asked Questions

What thread specification does the ATRM5-1.5 use, and why does it matter?

The ATRM5-1.5 is machined to a UNC Class 2A thread specification. This is a standard unified national coarse thread tolerance class, which means it is compatible with the nuts, couplers, take-up devices, and other hardware components commonly used in continuous rod tiedown and shearwall overturning restraint systems. Using a standardized thread class reduces fit issues and simplifies hardware selection on the job site.

What does "Grade 55" mean for this all-thread rod?

Grade 55 refers to the rod's minimum yield strength of 55 ksi (55,000 pounds per square inch), as defined by the ASTM A36 material standard. The rod also carries a minimum tensile (ultimate) strength of 75 ksi. These values define the rod's load-carrying capacity and are used by structural engineers when calculating performance within seismic and wind-force-resistant systems.

Can the ATRM5-1.5 be used as an adhesive anchor rod?

Yes. In addition to its primary role as a tension transfer element in continuous rod tiedown and uplift restraint systems, the ATRM5-1.5 can be used as an adhesive anchor rod. The fully threaded design along the entire 18-inch length supports consistent bond surface contact when used with structural adhesive anchor applications.

Is the uncoated black steel finish appropriate for all installation environments?

The ATRM5-1.5 features an uncoated black steel finish with no protective coating applied. This makes it best suited for interior structural applications where moisture exposure is not a concern. For installations in corrosive, wet, or exterior environments, consult the applicable project specifications and engineering requirements to determine whether a coated or stainless alternative is more appropriate.