The Simpson 4X Adjustable Post Cap - Zmax Finish from Simpson is built to create a positive, secure connection between the top of a post and a beam, making it a reliable choice for structural framing in both new construction and retrofit applications. Engineered from 18-gauge steel with a ZMAX galvanized finish, this adjustable post cap is designed for use with nominal 4x lumber and eliminates the structural weakness associated with end-grain nailing. Per the AC series design, these connectors are always installed in pairs to deliver a balanced, structurally sound connection on both sides of the post.

Key Features

• Eliminates nailing into end grains - removes a common weak point in post-to-beam connections, resulting in a more structurally sound joint
• Stronger than angled nailing or screw fastening - provides a more secure hold than traditional field methods, giving builders confidence in long-term structural integrity
• Designed for nominal 4x lumber - sized specifically for standard 4x posts so the fit is predictable and installation stays straightforward
• Made from 18-gauge steel - delivers the rigidity and load-bearing capacity expected in structural post cap applications
• ZMAX galvanization offers extra corrosion resistance for exterior and treated-wood applications - the heavy-duty coating stands up to harsh outdoor conditions and the corrosive chemistry of pressure-treated lumber, extending the service life of the connection
• Always installed in pairs - ensures a balanced connection on both sides of the post, distributing load evenly for a more reliable structural assembly

Why This Product

• Purpose-built corrosion protection - the ZMAX galvanized finish is specifically suited for exterior environments and treated-wood framing, making this post cap a practical long-term solution where standard galvanization may fall short
• A stronger alternative to traditional fastening methods - by eliminating end-grain nailing and outperforming angled nailing or screw fastening alone, this connector provides a more dependable post-to-beam joint in load-bearing structures
• Versatile fit for new and retrofit projects - the adjustable design works in both new construction and existing post connections, reducing the need for separate hardware when updating or reinforcing a structure
• Trusted Simpson engineering - the AC series design requires paired installation to ensure a balanced, structurally sound connection, reflecting a connector system built with structural performance as the priority

Specifications

• Model Number: AC4Z
• Member Size: 4x
• Width: 3-9/16 in.
• Length: 6-1/2 in.
• Gauge: 18
• Coating/Finish: ZMAX
• Install With: 0.162 in. x 3-1/2 in. nails or #10 x 1-1/2 in. Strong-Drive SD screws (sold separately)
• Country of Origin: United States

Frequently Asked Questions

What size lumber is the AC4Z post cap designed for?

The AC4Z is designed for use with nominal 4x lumber, making it suitable for standard 4x posts in structural framing applications.

What fasteners are required to install the AC4Z post cap?

The AC4Z should be installed with 0.162 in. x 3-1/2 in. nails or #10 x 1-1/2 in. Strong-Drive SD screws.

Why must AC series post caps always be installed in pairs?

The AC series is designed to provide a positive connection between a beam and a post, and installing these connectors in pairs ensures a balanced, structurally sound connection on both sides of the post.

Is the AC4Z suitable for outdoor or treated-wood applications?

Yes. The AC4Z features ZMAX galvanization, which offers extra corrosion resistance specifically suited for exterior environments and applications involving treated wood.

Note: Product dimensions and/or nail or screw holes may differ from picture. Please see item description for specifications.