Have you ever found yourself in a situation where a seemingly minor field issue escalates into a major problem due to lack of prior information? The cost of fixing such issues at a later stage can be significantly higher, not to mention the distractions it creates from other essential tasks. To address this common challenge, the implementation of Quality Management Systems (QMS) is crucial. Hilti, a leading provider of construction solutions, offers a game-changing tool—the Nuron SIW 4AT-22 Cordless Impact Wrench with the smart Hilti Adaptive Torque Module SI-AT-22 (AT System). This innovative solution can help establish a more robust QMS by collecting crucial data points for each embed t-bolt installed on-site, to help enable prompt and more accurate error identification.


The Impact of Repetitive Tasks on Error Rates:
Studies have shown that the brain involuntarily switches to rest mode during repetitive tasks, increasing the likelihood of errors (1). When additional factors like time pressure, accessibility challenges, adverse weather conditions, and others are introduced, the probability of mistakes is further increased. 



The proper installation of curtain walls brackets (also known as anchor clip, anchor plate, matt anchor, etc.) often draws the attention of inspectors and consultants due to its importance and frequent occurrence of improper installation. Despite the common practice of manually spray painting the bracket after torquing the t-bolts, this method often falls short in ensuring accurate installation. The performance of fasteners (and structural performance of the façade) can greatly depend on the correct application of the required installation torque. Figure 3 illustrates different field issues due to improper installation of the curtain wall bracket:



The Benefits of the Hilti AT System: The Hilti AT System provides an array of benefits, enhancing the quality assurance process in field operations:

1.    Compliance: The AT System and Hilti Adaptive Torque Module (HAC) are covered by ICC-ESR 3520 (https://icc-es.org/report-listing/esr-3520/).
2.    Error Reduction: By helping automize a repetitive manual process, the probabilities of more consistent bracket and t-bolt installation are increased.
3.    Earlier Identification of Potential Field Errors: Thanks to its reporting functionality, the AT System aids in the early identification of potential field fixes related to t-bolt installation, allowing for additional timely remediation.
4.    Data Collection and Reporting: Each installation using the AT System can be recorded and documented, facilitating data analysis, and generating more comprehensive reports.
5.    Productivity: The AT System speeds up the bracket and t-bolt setting process, helping to reduce installation time by up to 30 percent.
6.    Worker Well-being: By reducing muscle fatigue associated with manual torque applications, the AT System helps promote a healthier and happier workforce.
7.    Versatility: The AT System is also compatible with other Hilti post-installed mechanical anchors, such as KB-TZ 2 and KB-1, expanding its utility and versatility.
8.    “Efficiency: While traditional impact torque wrenches are not recommended for setting anchor channel t-bolts(2), they are commonly utilized to approximate the required torque value before using a manual torque wrench to complete the installation process. This practice can result in over-torquing of the t-bolts. By utilizing the Hilti AT System, the field can securely set HBC t-bolts the preferred method without compromising the system’s integrity.” 

See Typical AT system Questions (https://ask.hilti.com/article/typical-hac-and-at-system-questions/jsopav) about the difference of the HAC qualified AT System vs traditional impact torque wrench.

The Adaptive Torque Module: The "brain" behind the Hilti SIW 4AT-22 Impact Wrench
At the heart of the Hilti AT System lies the AT module, which acts as a "brain" for the SIW 4AT-22 impact wrench. Figure 4 illustrates the components of this turnkey solution. The AT module is programmed to accommodate various t-bolt types and sizes, covering a vast majority of the HBC t-bolt portfolio. Once the user selects the specific t-bolt, either manually or by scanning a QR code on the product packaging, they simply pull the trigger to tighten the nuts. The SIW 4AT-22 impact wrench will automatically stop at the optimal setting value, helping ensure the correct bolt pretension is achieved.





To learn more about the AT System and typical questions, click on the link below:
https://ask.hilti.com/article/typical-hac-and-at-system-questions/jsopav


Ordering information can be found in the link below:
https://www.hilti.com/c/CLS_CORDLESS_TOOLS_7123/CLS_CORDLESS_TOOL_ACC_7123/CLS_CORD_IMPACT_WRENCHES_ACC_7123/r3414399


References
1)    BBC News (2008, April 222). Dull jobs really do numb the mind. (http://news.bbc.co.uk/2/hi/science/nature/7358863.stm)


Article written by Jesus Barreda P.E.
Jesus Barreda is the Director of Façade Business Development with over 10 years experience in façade engineering and design. Jesus holds a Bachelor and Master’s degree in civil engineering with structural emphasis from the University of Cincinnati and an MBA from the Washington State University and is a licensed professional engineer in the state of Ohio.