Description

Key Features

Predeflected Body

The body is predeflected during manufacturing, which helps virtually eliminate deflection under load from material stretch. That matters when you need a tighter, more predictable hold at critical wall and post connections.

Screws Included

This holdown ships with the required Strong-Drive SDS heavy-duty connector screws and a crescent washer. You are not guessing at fasteners, and you are not losing time hunting down the right hardware.

Built for Lateral Loads

The Simpson Strong-Tie HDU8-SDS2.5 Predeflected Holdown is made for shearwalls, braced-wall panels, and other lateral wood construction connections. It gives wood-to-wood assemblies a strong tie-down point where uplift and overturning resistance matter.

Overview

The Simpson Strong-Tie HDU8-SDS2.5 Predeflected Holdown is a heavy-duty holdown for wood construction, built to reinforce critical tie-down connections in shearwalls, braced-wall panels, and other lateral load applications. This is a holdown designed for resisting uplift and overturning forces in wood framing assemblies. Model Number: HDU8-SDS2.5.

What makes this model worth a hard look is how it gets strength on the job without the usual bolt-related hassle. Instead of relying on stud bolts that need countersinking at openings, the HDU design uses Simpson Strong-Tie Strong-Drive SDS heavy-duty connector screws. Those screws are supplied with the holdown, which helps ensure the connection is installed with the proper fasteners from the start. In practical terms, that means faster setup, less guesswork, and less chance of a field substitution that can compromise the connection.

The predeflected body is the big story here. Simpson builds the HDU so the body is already predeflected, which virtually eliminates deflection under load due to material stretch. For framers, builders, and engineers, that is not a throwaway detail. It helps the connection engage more directly when the wall system is loaded, instead of wasting movement in the hardware before the load is fully transferred.

This specific HDU8-SDS2.5 version is made from 10-gauge steel with a Zinc Galvanized, G90 finish. It has a 3 inch width, 16-5/8 inch height, and 3-1/2 inch base dimension. That puts it in the range for serious structural tie-down work where a compact footprint still needs to deliver real holding power. The steel thickness and formed shape are there for one reason: keep the load path direct from the wood member down to the anchorage.

Jobsite practicality is another plus. The HDU requires no additional washer, and the included hardware package for this model contains (20) 1/4 inch x 2-1/2 inch Strong-Drive SDS Heavy-Duty Connector screws plus (1) crescent washer. That is the kind of detail that saves real time when crews are moving fast. You open the box and have the main connection hardware in hand instead of piecing it together from separate bins.

For installation, Simpson notes that the SDS screws install best with a low-speed, high-torque drill equipped with a 3/8 inch hex-head driver. Lowe’s also lists installation with a 7/8 inch anchor bolt and the included 1/4 inch x 2-1/2 inch SDS screws. That makes the intended use pretty clear: this is not general hardware for light fastening. It is a purpose-built structural connector for wood-to-wood tie-down assemblies where the anchorage and fastener package are part of a tested system approach.

The galvanized G90 finish adds corrosion resistance for standard applications, and Simpson also notes the HDU family is available in versions with additional corrosion protection. For this SKU, the finish is zinc galvanized, which is the right fit when you need coated steel hardware for typical protected framing conditions and want the standard factory configuration listed for the HDU8-SDS2.5.

If you are a framing contractor, builder, structural repair crew, or serious remodeler working on high-wind construction or other lateral-force details, this holdown makes sense. It is especially useful when you want a cleaner installation than a bolted holdown, when you care about reduced slip, and when you need supplied fasteners that match the connector. If you are just looking for a generic bracket, this is overkill. If you need a real structural holdown for code-driven wood construction details, this is the right category of hardware.

See the Load Path Clearly

This is the kind of connector you use when the connection matters as much as the framing itself. The HDU design ties the wood member down into the anchorage path instead of leaving that critical load transfer to lighter hardware.

• Designed for shearwalls, braced-wall panels, and other lateral applications
• Wood-to-wood holdown configuration with anchor-bolt-based tie-down installation

Faster Than Bolted Field Work

The included SDS screws are a practical advantage, not just a packaging note. They install more easily than a comparable bolt-heavy setup and help reduce fastener slip while preserving more of the post section than through-bolting.

• Includes (20) 1/4 inch x 2-1/2 inch Strong-Drive SDS Heavy-Duty Connector screws
• No stud bolts to countersink at openings

Predeflected for a Tighter Connection

The formed body is built to minimize wasted movement when the assembly is loaded. That helps deliver a more immediate, predictable connection response in structural framing where deflection control matters.

• Predeflected body virtually eliminates deflection due to material stretch
• 10-gauge steel body with zinc galvanized G90 finish

What’s in the Box

• (1) Simpson Strong-Tie HDU8-SDS2.5 holdown
• (20) 1/4 in. x 2-1/2 in. Strong-Drive SDS Heavy-Duty Connector screws
• (1) Crescent washer

Anchor bolt is part of the installation detail and is not listed as an included component for this SKU.

Key Specifications

Tool Type	Predeflected holdown
Material	Steel
Finish	Zinc Galvanized, G90
Gauge	10 ga.
Width	3 in.
Height	16-5/8 in.
Base Dimension	3-1/2 in.
Package Quantity	1

Compatibility

Materials Connected

Designed for wood-to-wood structural connections.

Fastener System

Uses 1/4 in. x 2-1/2 in. Strong-Drive SDS Heavy-Duty Connector screws, which are included with the holdown.

Installation Anchor

Lowe’s lists installation with a 7/8 in. anchor bolt.

Washer Requirement

The HDU requires no additional washer beyond the included crescent washer.

Built For

High-Wind Construction Shearwalls Braced-Wall Panels Lateral Load Connections Wood Framing General Contracting Remodeling Structural Repairs

Pro Tip

Use a low-speed, high-torque drill with a 3/8 inch hex-head driver for the SDS connector screws. It makes installation smoother and helps seat the screws cleanly without fighting the connection.

At a Glance

16-5/8 in.

Height

10 ga.

Steel Thickness

20

Included SDS Screws

3 in.

Width

Tool Nut’s Take

Tool Nut’s Take

Simpson Strong-Tie HDU8-SDS2.5 Predeflected Holdown Keeps Structural Tie-Down Work Simple

This is a purpose-built structural connector that earns its keep by giving you the right screws in the box, a cleaner installation than old-school bolt-heavy setups, and less connection movement when the load shows up.

• Who it’s for: Framers, builders, and remodelers handling shearwall, braced-wall, and high-wind wood framing details.
• Why it stands out: The predeflected body and included SDS screws make this holdown faster to install and more practical than connections that depend on extra bolt work and field improvising.
• Worth knowing: This is structural hardware, not a generic bracket. Make sure your anchor and framing detail match the engineered application you are building.

Common Questions

• What is this product used for? It is used in shearwalls, braced-wall panels, and other lateral wood construction applications where uplift and overturning resistance are required.
• Are the SDS screws included? Yes. This HDU8-SDS2.5 includes (20) 1/4 in. x 2-1/2 in. Strong-Drive SDS Heavy-Duty Connector screws and (1) crescent washer.
• Does this holdown need an additional washer? No. Simpson states the HDU requires no additional washer.
• What finish does this model have? This SKU uses a Zinc Galvanized, G90 finish.