Simpson HHDQ11-SDS2.5 HHDQ 15-1/8 in. Heavy Holdown with Strong-Drive SDS Screws is a Simpson Strong-Tie heavy holdown engineered for extra-high load applications. Installed directly on the sill plate, this holdown is ideally suited for back-to-back applications where eccentricity is a concern, and comes complete with Strong-Drive SDS Heavy-Duty Connector screws to simplify installation and ensure proper fastener use from the start.

Key Features

• Strong-Drive SDS Heavy-Duty Connector screws are supplied with the holdowns to ensure proper fasteners are used
• Screws may be installed either flush or raised off the mudsill without a reduction in load value
• No stud bolts to countersink at openings
• Height: 15-1/8 in.
• Holdown made from 7-gauge steel, with 1/2-in. plate washer
• Simpson Strong-Tie gray paint finish
• Strong-Drive SDS screws install easily, reduce fastener slip, and provide a greater net section than bolts
• Suitable for back-to-back applications where eccentricity is a concern
• Made in the United States

Specifications

• Model Number: HHDQ11-SDS2.5
• Height: 15-1/8 in.
• Material: 7-gauge steel
• Plate Washer: 1/2 in.
• Finish: Simpson Strong-Tie Gray Paint
• Coating: Simpson Strong-Tie Gray Paint
• Install With: (1) 1 in. anchor bolt and (24) 1/4 in. x 2-1/2 in. Strong-Drive SDS Heavy-Duty Connector screws
• Width: 3 in.
• Seat Depth: 3-1/2 in.
• Centerline: 1-1/2 in.
• Screw Offset: 7/8 in.
• Country of Origin: United States

What's Included

Each pack contains (1) HHDQ11-SDS2.5 Heavy Holdown, (24) 1/4 in. x 2-1/2 in. Strong-Drive SDS Heavy-Duty Connector screws.

Downloads and Resources

• View Specifications

Frequently Asked Questions

What type of fasteners are used with the HHDQ11-SDS2.5?

The HHDQ11-SDS2.5 installs using 1/4 in. x 2-1/2 in. Strong-Drive SDS Heavy-Duty Connector screws, which are included with the holdown. These screws install easily, reduce fastener slip, and provide a greater net section than bolts. A 1 in. anchor bolt is also required for installation.

Can the screws be installed raised off the mudsill without affecting performance?

Yes. Screws may be installed either flush or raised off the mudsill without a reduction in load value, providing flexibility during installation.

Is the HHDQ11-SDS2.5 suitable for back-to-back installations?

Yes. The HHDQ is installed directly on the sill plate and is specifically suitable for back-to-back applications where eccentricity is a concern.

What gauge steel is used in the construction of this holdown?

The holdown is made from 7-gauge steel and includes a 1/2-in. plate washer, providing the structural strength needed for extra-high load applications.