From Drawings to Installation:Best Practices for Power-ActuatedFastener Selection

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Post-installed connections are a cornerstone of modern engineering, with traditional anchors, such as wedge, screw, and adhesive types, commonly relied upon for high-capacity applications in concrete, masonry, and steel. While these anchors deliver robust performance, their installation often demands time-consuming predrilling which can expose workers to hazardous silica dust. In the case of adhesive anchors, extended curing periods based on the substrate temperatures can delay loading. For lighter, repetitive connections, power-actuated fasteners (PAFs) can be used for rapid, dust-free installation and significant labor savings when compared to pre-drilled connections. Recent advancements in PAF technology have further enhanced their versatility and safety, making them increasingly relevant for a wide range of structural and non-structural applications. PAFs are now routinely used to attach cold-formed steel, wood members, ceiling clips, MEP wire systems, and threaded studs to various substrates, including concrete, steel, masonry, and composite materials. However, the proliferation of PAF options and the complexity of field conditions mean that engineers must balance detailed specification with practical installation realities.

PAFs are specialized pins engineered to rapidly and securely attach materials to substrates such as concrete, steel, or masonry using tools powered by powder loads, gas canisters, or batteries. Unlike traditional anchoring systems, where the anchor type is selected based on the application and substrate, PAF systems are unique in that the fastener (pin) remains fundamentally similar across applications, while the tool used to drive the pin can vary significantly. Each tool is designed to accommodate a specific range of pin diameters and lengths, and in some cases, pins are engineered to fit only a particular tool or brand. Therefore, proper specification requires engineers to select the appropriate pin for the substrate and application; and installers to select the compatible tool system that delivers the required driving energy and installation control. This dual-selection process is critical for optimal performance, safety, and code compliance on the jobsite.

PAF tools operate on two primary driving principles: direct acting and indirect acting. In direct acting tools, the energy from the ignited powder load is transferred directly to the fastener, propelling it into the base material at high velocity. While this method enabled penetration into very dense concrete and thick steel, it also introduced significant safety hazards, including uncontrolled depth and risk of ricochet, which is why direct acting tools are no longer commercially available.

Modern PAF systems are classified as low-velocity, indirect acting devices. In these tools, the energy from the powder load is absorbed by a captive piston, which then drives the fastener into the substrate. This mechanism limits the fastener velocity (typically below 328 ft/s), providing much greater control over penetration depth and dramatically enhancing safety for both the operator and the surrounding structure.

The performance of PAFs in steel substrates is governed by a combination of geometric, material, and installation parameters that collectively determine the connection’s load-carrying capacity and reliability. Key factors include the thickness and tensile strength of the steel, the shank diameter and material of the fastener, the depth of penetration, and the spacing and edge distance relative to the steel member. When a fastener is driven into steel, it displaces the surrounding material laterally, creating a 360-degree frictional grip along the shank. This friction is further enhanced if the fastener features a knurled surface, which increases mechanical interlock. The installation process also generates significant heat at the interface, which can result in localized fusion between the fastener and the steel substrate, further improving holding strength.

In concrete substrates, the performance is primarily influenced by the compressive strength of the base material, the hardness and distribution of aggregate, the fastener’s shank diameter and embedment depth, and the prescribed spacing and edge distances. Upon installation, the fastener penetrates the concrete, displacing and compacting the material around the embedded portion of the shank. This action creates a zone of high compressive stress, which, together with the frictional resistance and localized fusion caused by installation heat, secures the fastener in place. The same principles generally apply to masonry substrates, though the variability in unit strength and the presence of hollow cores require additional caution and reliance on manufacturer testing data. Ultimately, the interplay of these factors dictates the overall performance, durability, and safety of PAF connections in concrete and similar materials.

When addressing code compliance and design considerations for PAFs, design engineers must recognize that, unlike other post-installed anchors, PAFs are not directly covered by Chapter 17 of American Concrete Institute’s (ACI) 318 Building Code Requirements for Structural Concrete and Commentary. This is a common misconception, as Chapter 17 focuses on anchorage to concrete but specifically excludes PAFs from its scope. Instead, engineers must look to other standards and acceptance criteria to guide the specification and design of PAF connections. For starters, ASTM E1190 Standard Test Methods for Strength of Power-Actuated Fasteners Installed in Structural Members provides standardized test methods for determining the static axial tensile and shear strengths of PAFs installed in concrete, masonry, and steel, as well as guidance on minimum spacing and edge distance. Other than that, AISI S100 North American Specification for the Design of Cold Formed Structural Members offers some guidance, but its provisions are limited to steel-to-steel applications and do not extend to concrete or masonry substrates, except for pull-over and bearing capacities.

In the absence of comprehensive code direction, the industry relies on ICC-ES Evaluation Service Reports (ESRs), which are based on the acceptance criteria outlined in AC70 Acceptance Criteria for Power-actuated Fasteners which is specifically developed for PAFs driven into concrete, steel, and masonry elements. AC70 consolidates the relevant design provisions for both structural and non-structural attachments and serves as the foundation for manufacturer testing and evaluation. When products are tested and shown to comply with AC70, ICC-ES publishes ESRs that provide rigorously validated values for tension, shear, embedment, edge distance, and spacing for each fastener and substrate combination.

When designing PAFs in steel, several key parameters will enhance both safety and performance. Per ASTM E1190, the steel substrate should have a minimum thickness of 1/8 inch to provide adequate anchorage and prevent punch-through. Fasteners must be placed at least ½ inch from any edge to avoid local yielding or tearing, and a minimum spacing of 11/2 inches to prevent stress concentrations and potential failure of the steel member.

In concrete applications, ASTM E1190 dictates maintaining a minimum edge distance of 3 inches to prevent spalling or blowout and ensuring the base material thickness is at least three times the fastener embedment depth to provide sufficient holding power and avoid breakout failures. These are the minimums, but actual performance data may differ, and engineers should check the manufacturer’s data per applicable PAF. For both tension and shear applications in concrete, the use of redundant fasteners is strongly recommended to enhance connection reliability and distribute loads more effectively across the substrate.

Lastly, for projects in high seismic regions, ASCE 7 Minimum Design Loads and Associated Criteria for Buildings and Other Structures and the applicable ICC-ES evaluation reports developed in accordance with ICC-ES AC70 impose additional restrictions on the use of PAFs. When seismic forces must be considered, PAFs are generally not permitted for attachments to masonry that resist seismic loads. When installed in concrete or steel, they are typically prohibited from carrying sustained tensile loads or serving as brace attachments for seismic-force-resisting systems. However, ASCE 7 provides limited exceptions for certain redundant nonstructural installations, such as suspended ceiling systems and other distributed attachments, where the load on an individual fastener remains within prescribed limits. In addition, some nonstructural components are exempt from Chapter 13 seismic design requirements depending on the structure’s Seismic Design Category and the component classification. Accordingly, proper specification of PAFs requires careful review of the manufacturer’s evaluation report, applicable acceptance criteria, and project-specific code requirements.

Designers must specify the correct fastener for each substrate, including all minimum required details, to ensure straightforward and accurate procurement by end-users and to support code-compliant installation. For example, when attaching a bottom cold-formed steel (CFS) track to concrete, the specification should include the fastener’s shank diameter, minimum embedment, required spacing, and the appropriate edge distance for concrete. Edge distance requirements differ between concrete and steel, so these must always be clearly indicated on the drawings. Additionally, in cases where powder-actuated fasteners are used, the specification should also direct installers to select the appropriate powder load level to achieve optimal performance and avoid overdriving or underdriving the fastener.

As an example, referring to Figure 4, the specification should state: “T bottom track-to-concrete connections, use 0.157-inch-diameter DEWALT CSI drive pins with a minimum embedment of 11/4 inches, spaced at 8 inches on center, and maintain a minimum edge distance of 3 inches. Use appropriate powder load in accordance with the manufacturer’s recommendations.”

In addition to project-specific fastening requirements, engineers should consider including the following notes in the “Post-installed anchors and fasteners” section on their Structural General notes sheet(s):

While the designer is responsible for specifying the fastener type, diameter, embedment, spacing, edge distances, and, where applicable, required capacities, the means and methods of installation should generally remain the responsibility of the certified installer. The general notes are intended to establish minimum installation requirements while directing installers to the manufacturer’s published guidance for project-specific procedures and limitations.

The certification requirement is particularly important because powder-actuated tools use controlled explosive charges to install fasteners and, therefore, demand specialized knowledge and safe operating practices. Regulatory organizations such as OSHA and ANSI have established stringent requirements governing their use, including provisions that limit operation to properly trained and qualified personnel. Certification helps ensure that installers understand tool operation, safe handling practices, fastener selection, loading and firing procedures, substrate suitability, inspection requirements, and emergency response protocols. By specifying certified installers, design professionals can help improve installation quality, reduce jobsite hazards, and increase confidence that the fastener system will perform as intended.

Even with proper planning and specification, field conditions can influence installation quality and fastener performance. Common issues include fishhooking, where a fastener bends during installation; spalling, which results in localized chipping or breakout of the concrete or masonry substrate; spring action associated with fastening into long, unsupported steel members; and difficulties encountered when fastening into steel that has been altered by welding or torch cutting. If not properly addressed, these conditions can reduce installation quality, holding strength, and overall connection reliability.

Although responsibility for identifying and resolving these issues typically rests with the installer, designers can support successful installations by providing clear fastening requirements and referencing approved manufacturers and evaluation reports. Because installation procedures and acceptance criteria vary among manufacturers and fastening systems, the manufacturer’s published installation instructions should remain the primary resource for tool selection, powder load selection, substrate evaluation, troubleshooting, and installation practices necessary to achieve the intended fastener performance in the field.

PAFs have become a trusted solution for attaching materials to steel, concrete, and masonry, but their reliability depends on both precise engineering specification and diligent installer practices. Engineers should always reference manufacturer ICC-ESR reports for tested values, specify all critical details such as fastener type, embedment, spacing, and edge distance, and ensure code compliance for every application. Equally important, installers must be properly trained and certified, select the correct powder load and tool, perform center punch tests to confirm material suitability, and follow the best practices for troubleshooting issues like fishhooking or spalling. Leveraging resources from manufacturers ensures that every connection is safe, efficient, and code compliant. By following these guidelines and consulting with experts when needed, both engineers and installers can deliver high-performing, reliable PAF solutions for modern construction. ■

Vinay Damam, PE, is an Associate and Senior Engineer with the Structures Group at HKS, having previously served as a Senior Field Engineer at DEWALT.

Stephanie Ecker, PE is a Field Engineering Solutions Manager at DEWALT.