The Simpson Strong-Tie ATRM8-3 ATRM 1 in. x 36 in. All-Thread Rod, Grade 55 is a fully threaded steel rod engineered to serve as a tension transfer element in structural systems designed to resist seismic and wind forces. Built from uncoated black steel to ASTM A36 standards, this all-thread rod provides a continuous and reliable load path from roof to foundation - making it a trusted component in continuous rod tiedown systems for shearwall overturning restraint, uplift restraint systems for roofs, and adhesive anchor rod applications. Whether you are reinforcing a structure against lateral wind loads or anchoring a shearwall assembly, this precut 36-inch threaded rod delivers the structural integrity required for demanding residential and commercial building applications.

Key Features

• Precut 36 in. length - ready to install without field cutting, saving time and reducing on-site labor during structural assembly.
• Grade 55 specification - meets elevated yield strength requirements (Fy = 55 ksi), meaning the rod can carry greater tension loads before deforming, suitable for high-demand seismic and wind-resistant systems.
• UNC Class 2A thread specification - a standardized thread form that ensures consistent fit and compatibility with nuts, couplers, and other threaded hardware used in tiedown systems.
• ASTM A36; Fy = 55 ksi and Fu = 75 ksi - these verified mechanical properties give engineers and inspectors confidence that the rod meets code-recognized strength thresholds for structural applications.
• Uncoated black steel material - delivers a clean, bare steel surface well suited for interior structural applications and allows for field-applied coatings or adhesive bonding when used as an adhesive anchor rod.
• 1 in. rod diameter - provides the cross-sectional strength needed to handle significant tensile loads in overturning restraint and uplift restraint assemblies.

Why This Product

• Designed specifically for seismic and wind force resistance, this all-thread rod is a purpose-built tension transfer element - not a generic fastener - giving structural engineers and contractors a component that is already accounted for in load path design calculations.
• The precut 36 in. length eliminates the need for field cutting and threading, reducing installation time and the risk of thread quality issues that can arise from field fabrication.
• With both overturning restraint in shearwall systems and uplift restraint for roofs as recognized applications, a single rod type can address multiple structural connection needs within the same project.
• The Grade 55 rating with confirmed ASTM A36 mechanical properties (Fy = 55 ksi, Fu = 75 ksi) means structural inspectors and plan reviewers have documented values to reference during inspection, supporting smooth project approvals.

Specifications

• Brand: Simpson Strong-Tie
• MPN: ATRM8-3
• Product Class: Threaded Rod
• Rod Diameter: 1 in.
• Rod Length: 36 in.
• Material: Uncoated Steel
• Finish: Uncoated Steel
• Color: Black
• Thread Specification: UNC Class 2A
• Grade: Grade 55
• Material 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 system for shearwall overturning restraint
• Uplift restraint system for roofs
• Adhesive anchor rod applications
• Structural systems designed to resist seismic forces
• Structural systems designed to resist wind forces

Frequently Asked Questions

What thread standard does the ATRM8-3 use?

The ATRM8-3 uses a UNC Class 2A thread specification. This is a standardized Unified National Coarse thread form that ensures reliable compatibility with mating nuts, couplers, and other hardware commonly used in continuous rod tiedown and uplift restraint systems.

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

The ATRM8-3 meets ASTM A36 material standards with a minimum yield strength (Fy) of 55 ksi and an ultimate tensile strength (Fu) of 75 ksi. These values satisfy Grade 55 specifications and are suitable for structural tension transfer applications in seismic and wind-resistant building systems.

Can this threaded rod be used as an adhesive anchor rod?

Yes. In addition to its primary use in continuous rod tiedown systems and roof uplift restraint assemblies, the ATRM all-thread rod is suitable for use as an adhesive anchor rod, expanding its versatility across a range of structural and anchoring applications.

Does this rod come precut or does it need to be cut to length in the field?

The ATRM8-3 is precut to a 36 in. length, meaning it arrives ready for installation without requiring field cutting or threading. This saves installation time and ensures the thread quality is consistent along the full length of the rod.