The Simpson Strong-Tie ATRM8-1 All-Thread Rod is a fully threaded, precut Grade 55 steel rod engineered as a tension transfer element for structural systems that must resist seismic and wind forces. Measuring 1 in. in diameter and 12 in. in length, this uncoated black steel rod delivers a continuous and reliable load path from roof to foundation - making it a critical component in continuous rod tiedown systems for shearwall overturning restraint, uplift restraint systems for roof applications, and adhesive anchor installations.

Key Features

• Precut to 12 in. length - ready to install right out of the package, saving time on the job site without the need to cut or measure rod stock
• Meets Grade 55 specifications - delivers higher minimum yield strength (55 ksi) compared to standard Grade 36 requirements, supporting demanding structural load calculations
• UNC Class 2A thread specification - ensures consistent, reliable thread engagement with nuts and couplers used in continuous rod tiedown assemblies
• ASTM A36 material; Fy = 55 ksi and Fu = 75 ksi - provides verified, code-compliant tensile and yield values for structural design and engineering submittals
• Uncoated black steel finish - suited for interior and protected structural applications where a bare steel surface is acceptable for the installed environment
• 1 in. rod diameter - matches standard sizing requirements for strong-rod tiedown system hardware including bearing plates, rod couplers, and take-up devices

Why This Product

• Designed specifically as a tension transfer element for seismic and wind force-resisting systems, this all-thread rod integrates directly into a continuous load path from roof to foundation - a critical requirement in engineered shearwall and uplift restraint designs.
• The precut 12 in. length eliminates on-site cutting and reduces material waste, making it a practical choice when shorter rod segments are required within a continuous rod tiedown assembly.
• Grade 55 strength ratings (Fy = 55 ksi, Fu = 75 ksi) with ASTM A36 compliance give engineers and inspectors the documented material properties needed to satisfy code requirements for structural rod systems.
• Full-thread (all-thread) construction along the entire 12 in. length means the rod can be cut to any position within the threaded section without losing thread engagement - adding flexibility for adhesive anchor rod applications and other structural uses.

Specifications

• Brand: Simpson Strong-Tie
• MPN: ATRM8-1
• Rod Diameter: 1 in.
• Rod Length: 12 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
• 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 installations
• Structural systems designed to resist seismic and wind forces

Frequently Asked Questions

What is the difference between Grade 55 and standard Grade 36 for all-thread rod?

Grade 55 specifies a minimum yield strength of 55 ksi and a minimum tensile strength of 75 ksi per ASTM A36 requirements. This is higher than the 36 ksi yield threshold associated with standard Grade 36 designations, making Grade 55 rod appropriate for structural tiedown systems where higher tension capacity is required for seismic and wind load path designs.

Can the ATRM8-1 be used as an adhesive anchor rod?

Yes. The marketing description for this product explicitly lists use as an adhesive anchor rod as one of the approved applications, in addition to its primary role in continuous rod tiedown systems for shearwall overturning restraint and roof uplift restraint.

What thread form does the ATRM8-1 use?

The ATRM8-1 uses a UNC (Unified National Coarse) Class 2A thread specification. This is a standard thread form widely used in structural rod hardware, ensuring compatibility with corresponding nuts, couplers, and take-up devices commonly used in rod tiedown assemblies.

Is the ATRM8-1 suitable for exterior or treated lumber applications?

The ATRM8-1 is made from uncoated black steel with no protective coating or finish applied. This makes it best suited for interior or protected structural applications. For environments with exposure to moisture, treated lumber, or corrosive conditions, a coated or corrosion-resistant rod option should be evaluated.