The Simpson DIA50SS DIA Type 303/304 Stainless-Steel Drop-In Internally Threaded Anchor for 1/2-in. Rod is a flush-mount expansion anchor engineered for solid concrete base materials where a clean, surface-level finish is required after installation. Built from Type 303/304 stainless steel throughout, this internally threaded drop-in anchor provides reliable corrosion resistance and holding strength for structural fastening applications that demand both durability and a finished appearance.

Key Features

• Flush-mount expansion anchor design - sits perfectly at the surface after installation, eliminating protruding hardware for a clean, finished look in concrete applications
• Compatible with hand- and power-setting tools - gives installers the flexibility to choose the setting method that best fits the job, speeding up installation and reducing labor effort
• Fixed-depth stop bit compatibility - helps ensure the hole is drilled to the correct depth every time, reducing guesswork and minimizing installation errors
• Type 303/304 stainless steel construction - delivers strong resistance to corrosion and oxidation, making this anchor well suited for demanding environments where carbon steel would degrade
• Internally threaded for 1/2-in. rod or bolt connections - accepts standard 1/2-in. threaded rod with a UNC thread profile, providing a secure mechanical connection without external fasteners visible at the surface
• Requires a 5/8-in. drill bit for installation - a precisely sized hole ensures the anchor expands correctly and achieves full rated load capacity; oversized holes will make it difficult to set the anchor and will reduce the anchor's load capacity

Why This Product

• Purpose-built for flush-mount concrete fastening - the drop-in anchor design is specifically engineered for applications where the fastening point must sit at or below the concrete surface, making it the right tool for finish-sensitive structural connections
• Stainless steel inside and out - with both the anchor body and expander plug constructed from AISI 303 stainless steel, corrosion resistance is consistent throughout the entire assembly, not just on the exterior surface
• Straightforward installation with fewer errors - compatibility with fixed-depth stop bits and both hand- and power-setting tools means the anchor can be installed accurately and efficiently without specialized expertise
• Trusted Simpson engineering for structural confidence - designed to meet the chemical requirements of ASTM A582, this anchor offers verifiable material compliance for projects where documentation and code conformance matter

Specifications

• MPN: DIA50SS
• Material: Type 303/304 Stainless Steel
• Finish: Type 303/304 Stainless Steel
• Bolt/Rod Diameter: 1/2 in.
• Length: 2 in.
• Thread Length: 3/4 in.
• TPI: 13
• Drill Bit Diameter: 5/8 in.
• Thread Type: UNC
• Anchor Body Material: AISI 303 - meets chemical requirements of ASTM A582
• Expander Plug Material: AISI 303
• Packaging: Packs of 50 and Cartons of 200

Approved Applications

• Flush-mount fastening in solid concrete base materials
• Applications requiring internally threaded expansion anchors for 1/2-in. rod or bolt connections
• Projects where a flush surface finish is required after anchor installation

Frequently Asked Questions

What drill bit size is required to install the DIA50SS anchor?

A 5/8 in. drill bit diameter is required for proper installation of the DIA50SS drop-in anchor. Using an oversized hole will make it difficult to set the anchor and will reduce the anchor's load capacity.

What rod or bolt size is compatible with the DIA50SS?

The DIA50SS is designed for use with a 1/2 in. rod or bolt. The thread specification is UNC with 13 TPI (threads per inch) and a thread length of 3/4 in.

What material is the DIA50SS anchor made from?

The DIA50SS anchor body and expander plug are both constructed from AISI 303 stainless steel. The anchor body meets the chemical requirements of ASTM A582, providing strong corrosion resistance for demanding environments.

What is the minimum thread engagement required for the DIA50SS?

Minimum thread engagement should be equal to the nominal diameter of the threaded insert. For the DIA50SS, which accommodates a 1/2 in. rod, a minimum of 1/2 in. of thread engagement is recommended to ensure proper load performance.

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