The Simpson Strong-Tie HD9B HDB 14 in. Galvanized (G90) Bolted Holdown is engineered by Simpson Strong-Tie 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 holdown offers low-deflection performance across a range of load requirements and is well-suited for back-to-back applications where eccentricity is a concern.

Key Features

• Installed after the placement of concrete and framing is in place
• Can be installed directly on the sill plate or raised above it
• Self-jigging, ensuring the code-required minimum of seven bolt diameters from the end of the post when installed flush with the sill plate
• Features a unique seat design which greatly minimizes deflection under load
• Base made from 3/8-in. steel; body made from 7-gauge steel
• Galvanized (G90) finish provides corrosion resistance
• Suitable for back-to-back applications where eccentricity is a concern
• Install with 7/8 in. anchor bolt and 7/8 in. stud machine bolts

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.