Simpson HDU8-SDS2.5 HDU 16-5/8 in. 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 HDU8-SDS2.5 features a predeflected body that virtually eliminates deflection under load due to material stretch, delivering superior performance and structural integrity where it matters most.

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
• Galvanized (G90) for extra corrosion resistance

Specifications

• Model Number: HDU8-SDS2.5
• Height: 16-5/8 in.
• Gauge: 10
• Coating/Finish: Zinc Galvanized, G90
• 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-SDS2.5 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-SDS2.5 is pre-deflected during the manufacturing process, which virtually eliminates deflection under load due to material stretch. This means the holdown maintains its holding strength more consistently once installed and loaded, resulting in a more reliable and stable connection.

Why does this holdown use SDS screws instead of bolts?

The 1/4 in. x 2-1/2 in. 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. This improves both the ease of installation and the overall strength of the connection.

Are the fasteners included with this holdown?

Yes. The package includes (20) 1/4 in. x 2-1/2 in. Strong-Drive SDS Heavy-Duty Connector screws and (1) crescent washer, ensuring that the proper fasteners are always used with the holdown.

What material and corrosion protection does the HDU8-SDS2.5 have?

The HDU8-SDS2.5 is made from 10-gauge steel and features a Zinc Galvanized (G90) coating, which provides extra corrosion resistance for long-term durability in demanding construction environments.

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