The Simpson 4x Adjustable Post Cap from Simpson is engineered to create a positive, structural connection between a beam and a post, making it a dependable choice for both new construction framing and retrofit applications where added structural support is needed. Designed specifically for nominal 4x lumber, this connector is always installed in pairs to ensure balanced load transfer at every post-to-beam joint. Built from 18-gauge steel with a G90 galvanized finish, it is well-suited for exposed or moisture-prone environments where long-term durability matters.

Key Features

• Eliminates nailing into end grains - reduces the risk of splitting lumber and produces a cleaner, more structurally sound connection
• Stronger than angled nailing or screw fastening - delivers superior load transfer compared to traditional field-fastening methods, giving builders greater confidence in structural performance
• Made from 18-gauge steel - provides a rigid, heavy-duty connector capable of handling the demands of post-to-beam structural applications
• G90 galvanized coating - offers extra corrosion resistance to help the connector hold up in damp, outdoor, or high-moisture conditions over time
• Designed for nominal 4x lumber - ensures a proper, consistent fit when connecting 4x posts to beams without guesswork or field modification
• Suitable for new construction and retrofit applications - gives contractors and builders flexibility to use this cap on fresh framing or to reinforce existing post-to-beam connections

Why This Product

• A more reliable connection than traditional fastening methods - by eliminating end-grain nailing and outperforming angled nailing or screw fastening, this adjustable post cap delivers a stronger, more dependable post-to-beam joint where structural integrity is critical
• Built for lasting performance in tough conditions - the G90 galvanized finish provides extra corrosion resistance, making this connector a smart choice for decks, pergolas, carports, and other outdoor structures exposed to the elements
• Versatile fit for new builds and existing structures - whether framing from the ground up or reinforcing a post-to-beam connection on an existing structure, this cap is designed to handle both scenarios without requiring a different product
• American-made quality from a trusted connector brand - manufactured in the United States by Simpson, a name widely recognized in structural connectors, giving builders and inspectors confidence in the product's engineering and consistency

Specifications

• Model Number: AC4
• Member Size: 4x
• Width: 3-9/16 in.
• Length: 6-1/2 in.
• Gauge: 18
• Coating/Finish: Zinc Galvanized, G90
• 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 lumber size is the AC4 post cap designed for?

The AC4 is designed for use with nominal 4x lumber, providing a secure connection between a 4x post and a beam.

What fasteners are required to install the AC4 post cap?

The AC4 post cap is installed with 0.162 in. x 3-1/2 in. nails or #10 x 1-1/2 in. Strong-Drive SD screws.

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

The AC series is designed to provide a positive connection between a beam and a post, and these connectors are always installed in pairs to ensure balanced structural support and load transfer on both sides of the post.

What makes the G90 galvanized coating beneficial for this post cap?

The G90 galvanized coating provides extra corrosion resistance, making the AC4 suitable for applications where exposure to moisture or the elements is a concern.

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