Hilti SIW 6AT-22 1/2 in Cordless Impact Wrench

The Hilti SIW 6AT-22 is a mid-torque cordless impact wrench with a 1/2 in friction ring anvil, 300 and 450 Nm maximum torque values and 650 Nm nut-busting torque. At 1.8 kg without battery and 182 x 72 x 220 mm, it is slimmer than the SIW 8-22 and is built for anchor setting and bolting up to M20.

Anchor setting and structural bolting in a compact body

Hilti lists setting HUS screw anchors in concrete for base plates, formwork props, handrails and temporary fixtures (8 to 16 mm), setting Hilti stud anchors in concrete with the SI-AT-22 Adaptive Torque module (M10 to M24), bolting steel for primary and secondary structures, handrails, racking and machinery (M10 to M20), and lag bolting in wood (8 to 16 mm).

The tool is described as 52 mm shorter and 0.4 kg lighter than its predecessor. Two speed modes give 0 to 1,550 rpm and 0 to 1,750 rpm no-load, with 3,100 and 3,500 impacts per minute. The tool is compatible with the Adaptive Torque module for more controlled fastening, but Hilti is explicit that an impact wrench must not be used for applications where an exact or maximum torque is specified, because of the risk of over-tightening and damage.

Technical specifications

Impact wrenches are not torque wrenches: selection notes

For bolting where a specified preload matters, such as flange joints or structural connections to a bolting specification, use a calibrated torque tool or the Adaptive Torque module appropriate to the application; the Hilti page states that an impact wrench should not be used where exact torque is required. Use the SIW 6AT-22 to run fasteners down and the correct torque method to finish them.

When quoting, confirm the battery and charger, the sockets (impact-rated 1/2 in square), and whether you need the SI-AT-22 module. For larger fasteners step up to the SIW 8-22 (1/2 in, 600 and 1000 Nm) or the 3/4 in SIW 10-22 and SIW 20-22.

Hilti impact wrench range by anvil and torque

Maximum torque values are quoted as printed on the Hilti UAE pages, where footnotes define the test condition of each figure.

Setting up the SIW 6AT-22 for site work

Before the tool goes to site, confirm that the batteries and charger issued with it are the ones specified in the operating instruction, and that every socket used on the 1/2 in friction ring anvil is impact-rated. Standard hand-tool sockets can crack under impact loading. Match the socket size to the fastener exactly and keep sockets clean, as worn or dirty sockets slip and round off nut corners.

Choose the speed mode for the task. The lower mode gives more control when starting anchors in concrete or running down smaller bolts, while the higher mode suits longer fasteners and lag bolting in timber. Start each fastener by hand or at low trigger pressure to avoid cross-threading, then let the tool run it down.

Using the tool with a torque procedure

Where a bolting specification sets a torque or preload, use the SIW 6AT-22 only to run fasteners down and complete the joint with the method the specification calls for. Where the job uses Hilti anchors with the SI-AT-22 Adaptive Torque module, follow the anchor setting instructions and the module documentation for each anchor type. Keep a record of the tools and methods used on structural connections so that inspectors can trace how each joint was made.

Working in Oman and GCC site conditions

Construction and maintenance sites in Oman and the GCC regularly expose tools to strong sun, high air temperatures and fine dust. Keep the tool and batteries out of direct sunlight between tasks and do not leave them in closed vehicles, since stored batteries can exceed the storage temperature listed in the specification table. Allow a hot battery to cool in the shade before charging it, and charge indoors or in a shaded, ventilated area.

Dust and sand reach the anvil, the trigger area and the battery contacts. Blow the tool off with dry air at the end of the shift, wipe the battery contacts and keep the tool in its case when not in use. On coastal and marine sites, wipe off salt spray and moisture before storage.

Inspection and maintenance checks

Check the anvil and friction ring for wear at regular intervals, because a worn ring no longer holds sockets securely and a socket can drop from height. Look for cracks or damage on the housing and battery packs and withdraw any damaged battery from use. Use the hearing protection appropriate to the sound level stated on this page, and follow the operating instruction for service intervals and repairs, which should be carried out by qualified service personnel.

Documents and quotation

For a quotation on the SIW 6AT-22, send Seven Star LLC the model, the supply voltage or battery set, the quantity and the delivery point in Oman or elsewhere in the GCC. Seven Star LLC is an independent supplier based in Muscat and does not hold any manufacturer status for Hilti. The Hilti operating instructions are attached as a multilingual PDF (an operating instruction, not a separate datasheet); current kit and item numbers should be read from the Hilti product page. Related fastening tools sit in the Material Handling & Lifting Equipment category.