Masonry Fastener

PROSOCO Masonry Fastener — 3/8-Inch Torque-Activated Post-Installed Anchor for Concrete and CMU

The PROSOCO Masonry Fastener is a 3/8-inch, post-installed masonry anchor engineered for contractors requiring reliable tension capacity in concrete, hollow CMU, grouted CMU, brick, tile, and steel substrates. Designed for deep wythe anchorage applications, it is available in multiple lengths to accommodate varying wall assemblies. This fastener is suited for restoration masonry, new construction anchorage, and wall tie applications where base material integrity is critical.

Unlike standard expansion anchors, the PROSOCO Masonry Fastener uses a 360 brass expander sleeve and cone that create a sympathetic, ductile connection to the base material, keeping unit stresses low and preventing premature cracking or failure. The torque-activated and torque-controlled installation method ensures consistent, repeatable performance across installations without overloading the substrate.

Technical Specifications

Key Features & Benefits

Torque-Activated and Torque-Controlled Installation

The fastener activates and seats through a controlled torque range of 50–100 in-lbs, removing guesswork from installation. For contractors, this means consistent anchor performance across every fastener placed, reducing the risk of under- or over-driving that could compromise load capacity.

High Anchor Stiffness for Demanding Structural Applications

With anchor stiffness reaching 50,000 lb/inch in hollow CMU and up to 100,000 lb/inch in concrete, this fastener minimizes deflection under load. High stiffness values are critical in wall tie and anchorage applications where movement between structural layers must be tightly controlled.

360 Brass Expander for Ductile, Sympathetic Load Transfer

The expander sleeve and cone are manufactured from 360 brass, a material selected for its ductile behavior under load. By conforming to the base material rather than forcing it apart, the brass expander keeps unit stresses low and actively prevents premature cracking or spalling of the surrounding substrate.

Corrosion-Resistant Construction

The 360 brass expander provides inherent corrosion resistance, and the choice of AISI 304 stainless steel bolt hardware extends that protection for exterior or moisture-exposed applications. Contractors can specify the appropriate hardware material to match the environmental exposure requirements of the project.

Multiple Lengths for Deep Wythe Anchorage

The fastener is available in multiple lengths, enabling use in deep wythe masonry wall assemblies where standard-length anchors cannot achieve adequate embedment. This flexibility makes it a practical single-product solution across varying wall thickness conditions on the same jobsite.

Low-Profile Design with Hex Bolt Finish Compatibility

The low-profile form factor and hex bolt finish compatibility allow the fastener to be used in applications where protruding hardware is a concern. The standard hex head also means installation requires no specialized tooling beyond a torque wrench or torque-limiting driver.

Common Applications

Masonry Restoration Anchorage

Post-installed into existing concrete or CMU walls, this fastener provides reliable tension capacity for re-anchoring deteriorated or displaced masonry wythes without requiring full reconstruction.

Deep Wythe Wall Tie Installation

Available in multiple lengths to reach through cavity wall assemblies, the fastener is well-suited for tying inner and outer wythes in restoration and new construction masonry projects.

Concrete Structural Attachment

With ultimate pullout strengths up to 3,377 lb in 7,500 psi concrete, the fastener provides substantial tension capacity for structural attachment points in concrete substrates.

Hollow and Grouted CMU Anchorage

Tested and rated in both 4-inch and 8-inch hollow CMU as well as grouted CMU, the fastener addresses the full range of concrete masonry unit wall assemblies encountered in commercial construction and renovation work.

Brick and Clay Tile Wall Anchorage

The ductile brass expander's sympathetic load transfer makes it suitable for anchoring into solid brick and clay tile, materials that are especially prone to cracking under aggressive mechanical anchor expansion.

Steel Substrate Fastening

Rated to 2,000 lb ultimate pullout in steel substrates 5/16-inch thick or greater, the fastener can serve as a unified anchoring solution across mixed-substrate wall assemblies.

Compatible Materials

• Concrete (normal and high strength)
• Hollow CMU (4-inch and 8-inch)
• Grouted CMU (8-inch)
• Solid brick
• Clay tile
• Steel (≥ 5/16-inch thick)

Product Documents

• Masonry Fastener Submittal Sheet (PDF)

Frequently Asked Questions

Q: What is the recommended installation torque for the Masonry Fastener?
A: The fastener should be tightened to 50–100 in-lbs as specified in the submittal documentation.

Q: What hardware material options are available?
A: The fastener is available with either zinc-plated steel (A307) hardware or AISI 304 (18-8) stainless steel hardware to suit varying environmental and corrosion-resistance requirements.

Q: What safety factor should be applied to the ultimate pullout strength values?
A: A safety factor of 4 is typically used to determine the allowable working load from the published ultimate pullout strength values. Site testing is encouraged to verify in-situ load capacity, as each construction site is unique.

Q: Can this fastener be used in tile and brick walls in addition to concrete and CMU?
A: Yes. The fastener is rated for use in solid brick and clay tile substrates, with published ultimate pullout strengths of 1,200 lb and 700 lb respectively.