The Simpson Adhesive Retaining Cap for 3/8 in. Rod and 1/2 in. Hole Diameter is a plastic accessory from Simpson that takes the frustration out of adhesive anchor installations in overhead, upwardly inclined, and horizontal orientations. By fitting over a 1/2 in. drilled hole, the cap contains anchoring adhesive inside the hole while simultaneously centering a 3/8 in. threaded rod or #3 rebar dowel during insertion - making it an essential tool wherever clean, precise anchor placement is required, including deep embedment applications.

Key Features

• Slit-through design allows the insert to pass while retaining adhesive - the cap keeps anchoring adhesive locked inside the hole during rod or rebar insertion, preventing messy runout and wasted material in gravity-challenged orientations.
• Built-in centering function positions the rod or rebar dowel accurately - the cap self-centers the insert within the drilled hole, reducing the risk of off-axis placement and delivering more consistent, reliable anchor results.
• Designed for overhead, upwardly inclined, horizontal, and deep embedment applications - a single cap type covers the most demanding installation orientations, reducing the need to stock multiple specialty accessories.
• Compatible with any Simpson anchoring adhesive - broad compatibility across the Simpson adhesive anchor product line means no guesswork about which adhesive system works with the cap.
• Supports use with the Simpson Piston Plug Delivery System - integrates with an established injection workflow, keeping the installation process organized and consistent from adhesive delivery through rod insertion.

Why This Product

• Solves the core problem of adhesive runout in non-downward installations - overhead and inclined anchoring without a retaining cap risks adhesive loss before the rod is even seated, compromising bond strength; this cap eliminates that risk by containing the adhesive throughout insertion.
• Doubles as a centering guide for precise anchor placement - for applications where anchor location tolerance is tight, the cap's centering action removes a manual alignment step and reduces costly placement errors.
• Works across multiple anchor types and adhesive systems - supporting both 3/8 in. threaded rod and #3 rebar dowels, and pairing with any Simpson anchoring adhesive, the cap fits into a wide range of structural and concrete anchoring projects without compatibility concerns.
• Made in the United States by a trusted structural connector brand - Simpson is a recognized name in construction fastening and anchoring, and this cap is produced domestically, offering confidence in quality for code-sensitive and inspection-required jobsites.

Specifications

• Model Number: ARC37-RP25
• Bolt/Rod Diameter: 3/8 in., #3
• Hole Diameter: 1/2 in.
• Drill Bit Diameter: 1/2 in.
• Material: Plastic
• Packaging: Packs of 25 and Cartons of 200
• Country of Origin: United States

Approved Applications

• Overhead anchor installations where adhesive must be retained in the hole
• Upwardly inclined anchor installations
• Horizontal anchor installations
• Deep embedment applications requiring precise anchor centering
• Installations using the Simpson Strong-Tie Piston Plug Delivery System
• Applications requiring precise placement of 3/8 in. threaded rod or #3 rebar dowels

Frequently Asked Questions

What is the purpose of the slit in the ARC37 adhesive retaining cap?

The slit in the cap allows the threaded rod or rebar dowel insert to pass through during installation while still containing the anchoring adhesive inside the drilled hole, preventing it from running out - especially critical in overhead and inclined orientations.

Can the ARC37 retaining cap support the weight of the anchor in overhead installations?

No. Adhesive retaining caps are not designed to support the weight of the anchor. In overhead installations, it is advisable to provide an adequate means of anchor support during the adhesive cure time.

Which Simpson Strong-Tie adhesives are compatible with the ARC37 retaining cap?

The ARC37 retaining cap works with any Simpson Strong-Tie anchoring adhesive, providing broad compatibility across the Simpson Strong-Tie adhesive anchor product line.

Can the ARC37 be used with the Simpson Strong-Tie Piston Plug Delivery System?

Yes. ARC adhesive retaining caps may be used in conjunction with the Simpson Strong-Tie Piston Plug Delivery System, offering a compatible and streamlined approach to adhesive anchor installations.