The Simpson 15 1/8 in Heavy Holdown with SDS2.5 Screws Stainless is a heavy-duty holdown connector engineered for extra-high load structural applications where both strength and corrosion resistance are non-negotiable. Built from 7-gauge steel with a stainless steel finish, this holdown is purpose-made for high-demand shear wall and lateral force resisting system connections, sill plate installations, and back-to-back configurations where eccentricity must be addressed. It arrives complete with Strong-Drive SDS Heavy-Duty Connector screws, pairing the holdown with the correct fasteners right out of the box for a code-compliant, ready-to-install solution.

Key Features

• 7-gauge steel construction with stainless steel finish - delivers the structural rigidity required for extra-high load connections while resisting corrosion in environments where standard steel finishes would fall short
• Supplied with Strong-Drive SDS Heavy-Duty Connector screws - eliminates fastener substitution errors on the job site by pairing the holdown with the correct screws before it ever leaves the box
• Sill plate-mount design - installs directly to the sill plate for a secure, low-profile placement that suits demanding shear wall assemblies
• Suitable for back-to-back holdown configurations - specifically engineered to address eccentricity concerns where two holdowns are installed in opposition, a detail that matters in critical lateral load applications
• SDS screw flexibility - included screws may be installed flush or raised off the mudsill without any reduction in load value, giving installers greater flexibility without compromising performance
• Domestic origin - designed and produced in the United States by Simpson, a trusted name in structural connectors

Why This Product

• A complete, job-site-ready package - because the correct Strong-Drive SDS Heavy-Duty Connector screws are included, contractors avoid the delay and risk of sourcing fasteners separately, and the pairing is correct by design rather than by guesswork
• Built for the toughest load demands - the extra-high load rating makes this holdown appropriate for the most structurally demanding shear wall and lateral force resisting system applications, where an undersized connector is not an option
• Stainless steel finish for lasting performance in harsh conditions - the stainless steel finish makes this holdown a sound long-term choice for corrosive environments where standard connectors would degrade over time
• Installation flexibility without performance trade-offs - the ability to install the included SDS screws raised off the mudsill with no loss of load value means field conditions do not force a compromise between proper placement and rated performance

Specifications

• Model Number: HHDQ11SS-SDS2.5
• Height: 15-1/8 in.
• Material: 7-gauge steel
• Finish: Stainless Steel
• Width: 3 in.
• Seat Depth: 3-1/2 in.
• Centerline: 1-1/2 in.
• Screw Offset: 7/8 in.
• Country of Origin: United States

Approved Applications

• Extra-high load holdown connections - ideal for high-demand shear wall and lateral force resisting system applications
• Sill plate installations - mounts directly to the sill plate for secure, low-profile placement
• Back-to-back holdown configurations - specifically suitable where eccentricity is a structural concern
• Corrosive environment framing - stainless steel finish makes this holdown appropriate for environments where standard steel finishes may be insufficient

What's Included

• 1x Simpson Strong-Tie HHDQ11SS-SDS2.5 Heavy Holdown (stainless steel)
• 1 in. anchor bolt
• 1/4 in. x 2-1/2 in. Strong-Drive SDS Heavy-Duty Connector screws

Frequently Asked Questions

What fasteners are included with the HHDQ11SS-SDS2.5?

The HHDQ11SS-SDS2.5 comes supplied with Strong-Drive SDS Heavy-Duty Connector screws, ensuring the correct fasteners are paired with the holdown right out of the box and eliminating the risk of substitution errors on the job site.

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

Yes. The Strong-Drive SDS screws included with this holdown may be installed either flush or raised off the mudsill without any reduction in load value, providing greater flexibility during installation.

Is this holdown suitable for back-to-back paired configurations?

Yes. The HHDQ11SS-SDS2.5 is designed to support back-to-back applications and is engineered to address eccentricity concerns that can arise in paired holdown configurations.

What material and gauge is the HHDQ11SS-SDS2.5 constructed from?

This holdown is constructed from 7-gauge steel with a stainless steel finish, providing enhanced corrosion resistance and making it well suited for applications where exposure to the elements or corrosive conditions is a concern.