The Simpson 1/4 x 2-1/2 Countersunk Split-Drive Anchor is a one-piece mechanical expansion anchor from Simpson engineered for fast, reliable installation into concrete, grout-filled block, and stone. Its split-type expansion mechanism compresses against the walls of a pre-drilled hole as the anchor is driven in, creating a secure mechanical hold without adhesives or secondary components. The countersunk head sits flush with the surface once installed, making this anchor well suited for attaching wood or light gauge steel to concrete and masonry surfaces where a clean, low-profile finish matters. Designed strictly for dry, interior, and non-corrosive environments, it delivers consistent performance in the structural applications where Simpson anchors are most trusted.

Key Features

• One-piece split-drive design - no loose parts or separate components means faster installation and fewer steps on the job site.
• Built-in expansion mechanism - compresses outward against the hole walls as the anchor is driven in, creating a secure hold without adhesives or mixing.
• Countersunk head - sits flush with the work surface after installation, producing a smooth, finished appearance when fastening wood or light gauge steel to masonry.
• Compatible with concrete, grout-filled block, and stone - covers the most common solid masonry base materials found in structural and interior construction applications.
• Zinc-plated carbon steel construction - provides a durable, corrosion-resistant finish appropriate for dry, interior, non-corrosive environments.
• Requires a 1/4 in. drill bit - the pilot hole diameter matches the anchor diameter exactly, simplifying tool selection and reducing prep time.

Why This Product

• Tool-free mixing, one-step installation - because the split-drive expansion mechanism works mechanically as the anchor is driven in, there is no adhesive to mix or cure time to wait for, keeping projects moving efficiently.
• Flush finish for clean, professional results - the countersunk head eliminates raised fastener heads that could interfere with attached materials or require additional finishing work.
• Trusted Simpson engineering - Simpson mechanical anchors are relied upon by specifiers and contractors for demanding structural applications, bringing that same proven performance to interior masonry fastening tasks.
• Straightforward sizing with no guesswork - the 1/4 in. anchor diameter and matching 1/4 in. drill bit requirement mean simple, consistent hole preparation every time.

Specifications

• Brand: Simpson Strong-Tie
• MPN: CSD25212
• Diameter: 1/4 in.
• Length: 2-1/2 in.
• Head Type: Countersunk Head
• Head Diameter: 1/2 in.
• Drill Bit Diameter: 1/4 in.
• Material: Carbon Steel
• Coating: Zinc Plated
• Finish: Zinc Plated
• Packaging: Packs of 100 and Cartons of 500

Approved Applications

• Concrete
• Grout-filled block
• Stone
• Attaching wood to concrete and grout-filled block surfaces
• Attaching light gauge steel to concrete and grout-filled block surfaces
• Dry, interior, and non-corrosive environments only

Frequently Asked Questions

What base materials can the CSD25212 Split-Drive Anchor be installed into?

The CSD25212 Split-Drive Anchor can be installed into concrete, grout-filled block, and stone. It is not intended for use in hollow CMU or other non-solid base materials without grouting.

What size drill bit is required to install this anchor?

A 1/4 in. drill bit is required to create the pilot hole for the CSD25212 Split-Drive Anchor prior to installation.

Is this anchor suitable for outdoor or corrosive environments?

No. The CSD25212 is finished with a zinc-plated coating and is designed for use in dry, interior, and non-corrosive environments only. It should not be used in wet, exterior, or chemically aggressive conditions.

How does the split-drive expansion mechanism work?

As the anchor is driven into the pre-drilled hole, the split-type expansion mechanism on the working end compresses and exerts outward force against the walls of the hole, creating a secure mechanical hold without the need for adhesives or additional hardware.

Note: Product dimensions may differ from picture. Please see the item description above for specifications.