How to Select A Proper Air Impact Wrench

1. The dynamic torque capacity specified for standard impact wrenches is generally measured at 90 PSI (6.3 kg/cm²) using maximum airflow, based on the cumulative torque generated after 5 to 10 seconds of tightening hard joints. However, this measurement may not fully reflect actual performance under soft or varied joint conditions.

2. When selecting a suitable air impact tool, it is crucial to consider the specific operating conditions, including: the actual working air pressure at the workstation, the size of the air hose and connector, the specifications of bolts, nuts, and washers, the joint’s hardness or softness, and the desired tightening time to achieve the target torque.

3. Correct Selection Method:

Simulate the actual workstation conditions (air pressure, hose size, bolt, nut, and washer combination) with the selected impact wrench. Measure its torque output using the ZIPPTORK’s TTT Digital Torque/Tension Tester to observe the torque curve and verify whether the tool is appropriate for the task. (Refer to the ZIPPTORK’s TTT demo video for guidance.)

4. When paired with a Wireless Rotary Torque Transducer:

Using an impact or hydraulic pulse wrench in conjunction with ZIPPTORK’s wireless torque rotary transducer allows the TTT Digital Torque Tester to be used for evaluation. It simultaneously displays the torque curve output from the transducer, providing a clearer view of the actual output torque performance under specified operating conditions.

5. Determining Maximum Output Torque:

Any air, electric, impact wrench, or hydraulic pulse tool can be assessed using either the ZIPPTORK’s TT Digital Torque Tester or the TTES Wireless Rotary Torque Transducer + TF Torque Fixture. A 1.5 to 2 second operation is sufficient to achieve the tool’s peak torque output under the current setup (hard joint).

Note: When utilizing an impact wrench for tightening soft joints, a longer duration is necessary to reach the tool’s maximum output torque.

How to Select a Static or Dynamic Wireless Rotary Torque Transducer

1. Static wireless rotary torque transducers:

For manual or geared torque wrenches, the torque rating of a static transducer indicates its maximum usable torque.

2. Dynamic wireless rotary torque transducers:

For air or electric impact wrenches, or hydraulic pulse tools, choose a dynamic wireless torque transducer by first testing the tool with the ZIPPTORK’s TT Digital Torque Tester under actual operating conditions (e.g., air pressure and hose setup).
The torque reading after a 2-second test should be increased by 20% (×1.2) to determine the required transducer specification. For example, if the 2-second reading is 140 Nm, select a transducer rated closest to 168 Nm (140 × 1.2 = 168), such as the TTES-180 (rated 180 Nm) or the TTES-250 (rated 250 Nm).

3. The chosen dynamic transducer must have a torque capacity approximately 20% higher than the output torque of the wrench to be utilized.

4. With ZIPPTORK’s TCA/TCB Torque Controller:

If the target torque is lower than the tool’s actual output under current conditions, the controller can operate in Transducer Mode. It will automatically shut off the air supply and determine the OK/NOK result once the target torque is achieved.

5. If the target torque exceeds the tool’s output torque, the controller will switch to Energy Accumulation Mode (ACCU Mode) or Substitute Mode. It is necessary to extend the tightening duration. During the tightening process, the controller continuously receives real-time signals from the torque transducer and calculates the accumulated energy corresponding to residual torque. Once the preset duration is reached, the controller automatically shuts off the air supply and compares the computed result against the target torque range to determine whether the operation is acceptable (OK/NOK).