The Simpson Lipped Drop-In Internally Threaded Anchor is a displacement-controlled expansion anchor engineered for fast, accurate, and economical installation into concrete and other base materials. Built by Simpson Strong-Tie with improved geometry for smooth and accurate seating, this internally threaded anchor accepts 1/4-in. threaded rod and is designed to reduce installation effort without sacrificing holding reliability. Whether you are anchoring suspended systems, equipment, or structural connections to concrete, the lipped design seats flush with the surface for a clean, professional finish.

Key Features

• Sets with 40% fewer hammer hits than previous drop-in anchor designs - reduces installation time and physical effort on the job, allowing crews to complete concrete anchoring work faster.
• Positive-set marking system - a visible indicator confirms the anchor has been fully and properly set, eliminating guesswork and reducing the risk of an under-set anchor.
• Lipped design for flush installation - the lip seats at the surface of the base material, ensuring a clean, level finish without the anchor protruding above the concrete.
• Zinc-plated carbon steel construction - provides a corrosion-resistant finish suitable for standard interior and protected concrete anchoring applications.
• Compatible with dedicated setting tools - installs with the DIABST hand-setting tool model DIABST25 or the power-setting tool model DIABST25-SDS, giving installers flexibility to choose manual or power-assisted setting.
• Accepts 1/4-in. threaded rod at 20 TPI - sized for common 1/4-in. rod and hardware, making it straightforward to match with standard fasteners and hanging components.
• Requires a 3/8-in. drill bit for hole preparation - a single consistent bit size simplifies setup and keeps tooling requirements to a minimum on the job site.

Why This Product

• Engineered for faster, lower-effort setting - the improved expansion plug geometry means this drop-in anchor drives home with significantly fewer hammer hits than older designs, cutting time per anchor and reducing fatigue during high-volume installations.
• Built-in confirmation of a proper set - the positive-set marking system gives installers immediate visual feedback that the anchor is correctly seated, supporting consistent, dependable results across every hole without relying on feel or experience alone.
• Flush-mount lip keeps finished surfaces clean - for applications where surface appearance or clearance matters, the lipped design prevents the anchor from standing proud of the concrete, making it a practical choice for suspended ceiling systems, mechanical supports, and other overhead or surface-mounted connections.
• A Simpson Strong-Tie anchor built around real-world installation efficiency - from the redesigned geometry to the tool compatibility with both hand and power-setting options, every aspect of this anchor is aimed at making concrete anchoring work quicker and more reliable on the job site.

Specifications

• Manufacturer Part Number (MPN): DIABL25
• Brand: Simpson Strong-Tie
• Bolt/Rod Diameter: 1/4 in.
• Length: 1 in.
• Thread Length: 3/8 in.
• TPI (Threads Per Inch): 20
• Drill Bit Diameter: 3/8 in.
• Material: Carbon Steel
• Coating/Finish: Zinc Plated
• Packaging: Packs of 100 and Cartons of 500

Frequently Asked Questions

What setting tools are required to install the DIABL25 anchor?

The DIABL25 installs with the DIABST hand-setting tool model DIABST25 or the power-setting tool model DIABST25-SDS. Using the appropriate setting tool drives the expansion plug toward the bottom of the anchor to achieve a proper, confirmed set.

How do I know when the DIABL25 anchor has been properly set?

The DIABL25 features a positive-set marking system - a visible indication marker located at the top of the anchor. Once the marker shows, you can confirm that the anchor has been properly and fully set in the base material.

What drill bit size is required for the DIABL25 drop-in anchor?

A 3/8 in. diameter drill bit is required to prepare the hole for the DIABL25 anchor. The anchor itself accepts a 1/4-in. threaded rod with 20 threads per inch (TPI).

What makes the DIABL25 faster to install than older drop-in anchor designs?

The DIABL25 features improved geometry in its preassembled expansion plug, which enhances the setting capability of the anchor. This redesign allows the anchor to be fully set with 40% fewer hammer hits compared to previous drop-in anchor versions, significantly reducing installation time and effort.

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