The TN series of tools from GWY are an excellent solution for executing precise and efficient turn of nut installations.
The tools most notable feature is the Angle Setting Dial. The feature allows us to specify the exact turn needed to achieve the required bolt tension. This manner of precise tensioning, accurate to a single degree, is unique to the turn-of-nut gun.
The turn of nut gun utilizes a reaction arm to efficiently create the torque needed to tighten fasteners. This is important to note when testing in a Skidmore because tools that use a reaction arm need additional testing equipment referred to as torque reaction kits. As you can see without anything to react against the tool will not function.
Skidmore torque reaction kits offer a variety of solutions to accommodate different sizes and lengths of reaction arms. In this case we are using the bar configuration that works well with the turn of nut gun’s shorter reaction arm. Regardless of the configuration used the most important feature of the torque reaction kit is that it mounts directly to the Skidmore unit. If you react against anything not directly attached to the Skidmore unit, your could be injured or damage to the Skidmore may result.
Once the reaction kit has been properly added to the Skidmore the tool can function as intended by reacting against the surface of the bar.
In this video we teat a 3/4 inch diameter bolt and since it is less than 3” in length it requires 1/3 of a turn to develop required tension. A 1/3 turn translates to 120 degrees which we have specified using the angle setting dial.
The video shows well over the 29,000 pounds force of tension required for a 3/4 inch diameter bolt and the 1/3 has been properly and precisely executed.
In further examples it can be seen that even without match marking the fastener, a proper turn is executed and bolt tension of 39,000 pounds force is achieved. This shows the precision and repeatability that can be trusted by specifying the exact turn required using the angle setting dial.
Another benefit of being able to precisely set the angle degrees is avoiding the guesswork that typically occurs when properly executing a match marked turn. Not having a clear indicator to line up with the match marks or having to reposition the tightening tool several times often results in multiple attempts and visual inspections of the required turn.
When the turn is controlled by the tightening tool it can be executed in one efficient process which can be quickly verified once complete.
Combining the TN series tools with a proper pre-installation verification testing creates an environment that supports successful and predictable turn-of-nut installations.
Visit the following links to learn more about Turn of Nut Wrenches and Skidmore Testing: