Simpson HDU8-SDS2.5HDG HDU 16-5/8 in. Hot-Dip Galvanized Predeflected Holdown with Strong-Drive SDS Screws is engineered by Simpson Strong-Tie for use in shearwalls, braced-wall panels, and other lateral applications in wood construction. The HDU holdown features a predeflected body manufactured to virtually eliminate deflection under load due to material stretch, while hot-dip galvanization delivers superior corrosion resistance for exterior and treated-wood applications.

Key Features

• Predeflected body virtually eliminates deflection due to material stretch
• Uses SDS screws, which install easily, reduce fastener slip and provide a greater net section area of the post compared to bolts
• SDS screws are supplied with the holdowns to ensure proper fasteners are used
• No stud bolts to countersink at openings
• Height: 16-5/8 in.
• Made from 10-gauge steel
• Hot-dip galvanization (HDG) offers extra corrosion resistance for exterior and treated-wood applications

Specifications

• Model Number: HDU8-SDS2.5HDG
• Height: 16-5/8 in.
• Gauge: 10
• Coating: Hot-Dip Galvanized
• Finish: Hot-Dip Galvanized
• Install With: Install with 7/8 in. anchor bolt and 1/4 in. x 2-1/2 in. Strong-Drive SDS Heavy-Duty Connector screws (included)
• Country of Origin: United States

What's Included

Each pack contains (1) HDU8-SDS2.5HDG Predeflected Holdown, (20) 1/4 in. x 2-1/2 in. Strong-Drive SDS Heavy-Duty Connector screws and (1) crescent washer.

Downloads and Resources

• View Specifications

Frequently Asked Questions

What does "predeflected" mean and why does it matter?

The HDU8-SDS2.5HDG holdown body is pre-deflected during the manufacturing process, which virtually eliminates deflection under load due to material stretch. This means the connector maintains its structural integrity more effectively once installed and loaded, compared to standard holdowns that can deflect over time.

Why are SDS screws used instead of bolts?

Strong-Drive SDS Heavy-Duty Connector screws install easily, reduce fastener slip, and provide a greater net section area of the post compared to bolts. There are also no stud bolts to countersink at openings, simplifying the installation process.

Is this holdown suitable for exterior or treated-wood applications?

Yes. The hot-dip galvanization (HDG) coating offers extra corrosion resistance, making the HDU8-SDS2.5HDG well suited for exterior and treated-wood applications where standard coatings may not provide adequate protection.

Do the required fasteners come with this holdown?

Yes. The holdown ships with (20) 1/4 in. x 2-1/2 in. Strong-Drive SDS Heavy-Duty Connector screws and (1) crescent washer to ensure the proper fasteners are used. A 7/8 in. anchor bolt is also required for installation but is not included.

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