The Simpson Strong-Tie ATRM 1/2 in. x 36 in. All-Thread Rod, Grade 55 is a fully threaded tension transfer element engineered by Simpson Strong-Tie for structural systems that must resist seismic and wind forces. By creating 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 roof applications. Its fully threaded profile along the entire 36-inch length also makes it suitable for use as an adhesive anchor rod and a wide range of other structural fastening applications.

Key Features

• Precut 36 in. length - ready to install without field cutting, saving time and labor on the jobsite
• Grade 55 specification - meets defined strength requirements (Fy = 55 ksi and Fu = 75 ksi per ASTM A36), giving engineers and installers confidence in load-rated structural performance
• UNC Class 2A thread specification - ensures consistent thread engagement and compatibility with standard nuts, couplers, and bearing plates used in tiedown assemblies
• ASTM A36 uncoated black steel construction - a proven, widely recognized steel standard that supports use in engineered structural applications where load path integrity is essential
• 1/2 in. rod diameter - a common diameter that integrates directly with Simpson Strong-Tie Strong-Rod Systems hardware, reducing the need for adapters or special fittings
• Fully threaded along entire length - allows flexible placement of nuts, couplers, and connectors anywhere along the rod, accommodating varied installation depths and system configurations

Why This Product

• Designed specifically as a tension transfer element within continuous rod tiedown systems, this threaded rod delivers a verified load path from roof to foundation - the kind of structural continuity required in seismic and high-wind design zones
• The Grade 55 rating with defined yield strength (Fy = 55 ksi) and tensile strength (Fu = 75 ksi) means structural engineers can specify this rod with confidence, knowing the mechanical properties meet recognized ASTM A36 standards
• Precut to 36 in. and fully threaded end to end, this rod eliminates field prep time and gives installers maximum flexibility for positioning connectors, couplers, or bearing hardware anywhere along its length
• Its versatility extends beyond shearwall restraint - the same rod can be deployed in roof uplift restraint systems and as an adhesive anchor rod, reducing the number of different components needed on a complex structural project

Specifications

• Brand: Simpson Strong-Tie
• MPN: ATRM4-3
• Rod Diameter: 1/2 in.
• Rod Length: 36 in.
• Material: Uncoated Steel
• Finish: Uncoated Steel
• Color: Black
• Thread Specification: UNC Class 2A
• Steel Standard: ASTM A36
• Yield Strength (Fy): 55 ksi
• Tensile Strength (Fu): 75 ksi
• Grade: Grade 55
• Product Class: Threaded Rod
• Quantity: 1
• Country of Origin: United States
• Prop 65: No

Approved Applications

• Continuous rod tiedown systems (Strong-Rod Systems) for shearwall overturning restraint
• Uplift restraint systems for roof applications
• Adhesive anchor rod applications
• General structural tension transfer in seismic and wind-force-resisting systems

Frequently Asked Questions

What is the thread standard for the ATRM4-3 all-thread rod?

The ATRM4-3 meets the UNC Class 2A thread specification. This is a standard Unified National Coarse thread profile, ensuring compatibility with the nuts, couplers, and bearing plates commonly used in continuous rod tiedown assemblies and other structural fastening applications.

What are the mechanical strength properties of this threaded rod?

The rod is manufactured to ASTM A36 standards with a Grade 55 designation. This means a minimum yield strength (Fy) of 55 ksi and a minimum tensile strength (Fu) of 75 ksi, providing the structural performance properties required for engineered load path applications.

Can this all-thread rod be used in applications other than shearwall tiedown systems?

Yes. While it is designed as a tension transfer element for continuous rod tiedown systems and roof uplift restraint systems, the ATRM4-3 can also be used as an adhesive anchor rod and in a variety of other structural applications where a fully threaded 1/2 in. steel rod is required.

Does the ATRM4-3 have any coating or corrosion protection?

No. The ATRM4-3 is an uncoated black steel rod with no applied finish or corrosion-resistant coating. It is intended for use in dry or protected interior structural applications typical of continuous rod tiedown systems within wood-framed construction.