Achieve ETA compliance for stud anchor installation into concrete with the new Adaptive Torque System

To install an anchor, your choices are between a slow torque wrench, a cumbersome torque bar, or a powered impact wrench which lets productivity soar but safety and reliability slump.

But now with Hilti's Adaptive Torque (AT) system, you won’t have to compromise.*

*Currently designed for select sizes of Hilti HST3 & HSL4 anchors only.  Contact Hilti for details.


The AT system is made up of four components:

  • The cordless impact wrench SIW 6AT-A22: it looks and works like the Hilti SIW 22-A cordless impact wrench but with intelligent electronics, a more robust anvil and a sleeker front which can reach into tighter spaces.
  • SI-AT-A22 module: a small, very light interface which slots in between the impact wrench and battery and processes live data from the SIW 6AT-A22 to recognise when an anchor has been correctly installed.
  • Documentation software so that the SI-AT-A22’s job history can be transferred to a PC and used to create a detailed installation report.
  • Hilti HST3 and HSL4 expansion anchors for cracked and un-cracked concrete.

AT-ready tools are equipped with the sensors and on-board intelligence to confirm if an anchor has been torqued according to ETA approvals. The operator simply inputs which anchor is being used – as easy as scanning the box with the SI-AT-A22’s integrated barcode reader – and the tool does the rest. Afterwards, the tool can be connected to a computer to instantly generate an installation report, offering inspectors, QA managers, and engineers higher confidence that the work has been carried out exactly as specified.

Simple, Fast, Effective

Select your anchor

Use the SI-AT-A22 module’s built-in scanner to read the barcode on your box of anchors. The SIW 6AT-A22 impact wrench then adjusts the torque setting to meet certification requirements. Tap the lock button to confirm your selection, and the impact wrench is ready to use

Pull the trigger

With the SIW 6AT-A22 impact wrench, all you need to do is pull the trigger and let the tool work. As soon as the SI-AT module lights up green, you know the anchor has been torqued to exactly the right level to comply with ETA approvals.

Adjust and retorque

Giving you confidence that the anchor has been correctly installed, sensors in the SIW 6AT-A22 recognise if an anchor has been loosened and, on retightening, will restore the correct torque. And with the AT System you can adjust and retorque up to two times.

Easily generate your installation report

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Full accountability has never been easier. Simply connect the SI-AT-A22 module to a computer using a standard Type-B USB cable and the AT Documentation Software then downloads performance data stored by the SI-AT-A22, which can be used to produce an installation report.

The report lists all products used, the method of selection (scan or manual) and completion time and date.  

From an engineer's perspective, this report proves that the anchors have been torqued correctly to certification report requirements. From an installer’s point of view, it can help you breeze through the setting and the site inspection process.

Changes encouraged

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The SIW 6AT-A22 is intelligent enough to detect an anchor which has been tightened and then loosened again - a function which is useful for straightening or aligning neighbouring fixtures, such as railings and windows.

During this process the SI-AT-A22 module uses an algorithm developed from more than 10,000 tests, to ensure no improper torqueing occurs when retightening an anchor. When the tool stops, it flashes a yellow light, a display notification and makes a sound, signalling the operator that the anchor has been retightened. With the SI-AT-A22, loosening and retightening HST3 and HSL4 anchors is allowed only twice, as indicated by the flashing yellow light. If a further attempt is made, the indicator flashes red, signalling a calibrated torque wrench must be used instead.

The anchor setting trifecta: SafeSet

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Safety. Productivity. Approval. SafeSet is Hilti’s proven methodology for consistently high-quality anchor installation at lightning speed.

The SIW 6AT-A22, along with the SI-AT-A22 module, fulfils all SafeSet criteria because they save time and reduce costs while also reducing the potential for installation error.

SafeSet technology is providing new ways for engineers and contractors to minimise installation errors.

Profis Engineering

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Hilti HST3 and HSL4 expansion anchors for cracked and un-cracked concrete.

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