The Simpson Heavy Tension Tie HTTH6.5 is a single-piece formed holdown engineered by Simpson for residential construction and light-framed wood commercial buildings. Tested per AC 155, this heavy tension tie is the first nailed-on holdown to achieve up to 7,650 lb. allowable load, delivering an economical path forward when heavier uplift and lateral loads are required. Fastened with nails sized for standard pneumatic nailers or Strong-Drive SD Connector screws, it simplifies installation without sacrificing structural performance.

Key Features

• Four-fold seat design - reduces deflection under load, helping the connection maintain tighter tolerances over the life of the structure
• Tapered base geometry - optimized for increased strength and reduced deflection, so the tie performs efficiently even at maximum allowable loads
• Engineered nailing pattern - minimizes splitting at the end of the post and maximizes individual fastener capacity, protecting the wood member and the connection simultaneously
• 0.185-in. fastener hole diameter - compatible with both standard nails and Strong-Drive SD Connector screws, giving installers flexibility to use whichever fastener type is on the job site
• 10-gauge steel construction - provides the heavy-duty thickness needed to handle demanding load requirements in structural wood framing applications
• G90 zinc galvanized finish - delivers reliable corrosion resistance, extending the service life of the connector in exposed or moisture-prone framing conditions
• Works with a standard 3/4-in. anchor rod and cut washer - connects directly to common foundation anchor hardware, keeping procurement straightforward for builders and contractors

Why This Product

• Record allowable load for a nailed-on holdown - at up to 7,650 lb. allowable load per AC 155 testing, this tension tie opens the door to heavier load conditions without requiring a more complex or costlier connection system
• Dual fastener compatibility saves time on site - the 0.185-in. hole diameter accepts both nails in standard pneumatic nailer sizes and Strong-Drive SD Connector screws, so crews are not locked into a single installation method
• Structural details work together to protect the wood - the tapered base, four-fold seat, and optimized nail pattern collectively reduce deflection and post-end splitting, meaning fewer callbacks and stronger long-term performance
• Purpose-built for residential and light commercial framing - designed specifically for the load ranges and framing configurations typical in wood-framed homes and commercial structures, making it a reliable specification choice for both project types

Specifications

• Model Number: HTTH6.5
• Gauge: 10
• Length: 20-1/4 in.
• Width: 3 in.
• Anchor Rod Diameter: 3/4 in.
• Fastener Hole Diameter: 0.185 in.
• Coating: Zinc Galvanized, G90
• Finish: Zinc Galvanized, G90
• Material: 10-gauge steel
• Install With: (1) 3/4-in. anchor bolt AND (34) 0.148 x 2-1/2-in. nails, 0.162 x 2-1/2-in. nails, #10 x 1-1/2-in. Strong-Drive SD screws or #10 x 2-1/2-in. Strong-Drive SD screws
• Country of Origin: United States

Downloads and Resources

• Fasteners required. View Specifications

Frequently Asked Questions

What is the maximum allowable load for the HTTH6.5?

The HTTH6.5 is the first nailed-on holdown to achieve up to 7,650 lb. allowable load, making it an economical solution when heavier loads are required in residential and light-framed wood commercial construction.

What fasteners are compatible with the HTTH6.5?

The HTTH6.5 features a 0.185-in. fastener hole diameter, making it compatible with both nails and Strong-Drive SD Connector screws. Specifically, it can be installed with (34) 0.148 x 2-1/2-in. nails, 0.162 x 2-1/2-in. nails, #10 x 1-1/2-in. Strong-Drive SD screws, or #10 x 2-1/2-in. Strong-Drive SD screws, along with (1) 3/4-in. anchor bolt.

Does the HTTH6.5 require a washer?

Yes, the HTTH6.5 requires one standard 3/4-in. cut washer for installation. Please note that this washer is not included with the tension tie.

What construction types is the HTTH6.5 suitable for?

The HTTH6.5 is an ideal solution for residential construction as well as light-framed wood commercial buildings. It has been tested per AC 155 and delivers high performance for wood-to-concrete tension connections where heavier loads are required.

Note: Product dimensions and/or screw or bolt holes may differ from picture. Please see item description for specifications.