Simpson Strong-Tie HD9B HDB 14 in. Galvanized (G90) Bolted Holdown is engineered to deliver reliable load performance for intermediate-load-range shearwalls, braced-wall panels, and lateral applications in wood construction. Installed with bolts into studs or columns, this bolted holdown provides low-deflection performance across a range of load requirements, and its design makes it well-suited for back-to-back holdown installations where eccentricity is a concern.

Key Features

• Installed after concrete placement and framing is in place - fits into the standard construction sequence without requiring pre-installation, saving time and reducing coordination challenges on the job site.
• Can be installed directly on the sill plate or raised above it - gives installers placement flexibility to meet varying project conditions without sourcing an alternative product.
• Self-jigging design - automatically ensures the code-required minimum of seven bolt diameters from the end of the post when installed flush with the sill plate, reducing layout time and helping keep the project code-compliant.
• Unique seat design that greatly minimizes deflection under load - helps maintain structural integrity and wall performance over time, which is especially critical in shearwall and lateral-load applications.
• Base made from 3/8 in. steel; body made from 7-gauge steel - the combination of a heavy base with a robust body provides the strength hierarchy needed to handle intermediate load ranges without oversizing the connector.
• G90 zinc galvanized finish - provides a corrosion-resistant coating that helps protect the connector in demanding installation environments, supporting long-term durability.
• Installed with 7/8 in. anchor bolt and 7/8 in. stud machine bolts - uses standard, readily available fasteners so crews can complete the installation without specialty hardware.

Why This Product

• Built for intermediate-load shearwall and lateral applications - rather than over-engineering for heavy loads or under-performing in light-duty roles, the HD9B is purpose-designed for the intermediate load range common in wood-framed shearwalls and braced-wall panels, giving engineers and builders a right-sized solution.
• Low-deflection performance through a proven seat design - the unique seat geometry actively reduces movement under load, which matters in lateral systems where excessive deflection can compromise wall performance and code compliance.
• Designed to address eccentricity in back-to-back installations - the HDB geometry is specifically suited for situations where two holdowns are installed on opposite faces of a post or column, making it a practical choice for double-sided shearwall connections without requiring custom modifications.
• Post-framing installation keeps the construction schedule on track - because the HD9B is installed after concrete and framing are in place, it does not require crews to coordinate anchor placement before framing begins, reducing the risk of costly rework.

Specifications

• MPN: HD9B
• Brand: Simpson Strong-Tie
• Height: 14 in.
• Width: 2-7/8 in.
• Gauge: 7
• Coating: Zinc Galvanized, G90
• Finish: Zinc Galvanized, G90
• Base Material Thickness: 3/8 in. steel
• Install With: 7/8 in. anchor bolt and 7/8 in. stud machine bolts
• Hole Bottom: 6-1/8 in.
• Seat Depth: 2-1/2 in.
• Centerline: 1-1/4 in.
• Screw Offset: 2-3/8 in.
• Country of Origin: United States

Approved Applications

• Intermediate-load-range shearwalls
• Braced-wall panels
• Lateral applications in wood construction
• Back-to-back holdown installations where eccentricity is a concern

Frequently Asked Questions

When is the HD9B holdown installed during construction?

The HD9B is installed after the placement of concrete and framing is in place, making it a straightforward addition to the construction sequence without requiring pre-installation before framing.

What fasteners are required to install the HD9B?

The HD9B is installed with a 7/8 in. anchor bolt and 7/8 in. stud machine bolts, securing the holdown firmly to both the concrete foundation and the wood framing members.

What makes the HD9B suitable for back-to-back applications?

The HD9B HDB is specifically designed with back-to-back applications in mind, addressing situations where eccentricity is a concern. Its construction and geometry allow it to perform reliably when two holdowns are installed on opposite faces of a post or column.

How does the HD9B minimize deflection under load?

The HD9B features a unique seat design that greatly minimizes deflection under load, contributing to its low-deflection performance across a range of load requirements - critical for maintaining structural integrity in shearwall and lateral applications.