What is a Torque Arm? Why You Need One to Improve Worker Safety

Work on assembly lines depends on repetition, and using power torque tools to perform the same task over and over is tiring. Employee fatigue dramatically increases the possibility of errors that reduce the reliability of the final product. These repetitive motions on assembly lines also carry the risk of repetitive stress injuries that can result in workman’s compensation claims. A solution that can stop these problems before they begin is a torque arm. 

What is a torque arm? A torque arm is a mount for a torque tool that supports it while allowing the operator to smoothly move the power torque tool around the work area to complete fastening operations. They can reduce worker fatigue, prevent injury, and improve productivity, making them an important factor to consider in stage-by-stage assembly line design.

 

What is a Torque Arm? The Different Types

There are a variety of torque arm types. These arms are attached to a vertical mast with one or more torque balancers at the top. Theses balancers allow the arm to be moved vertically up and down the mast with very little effort, and they hold the torque arm in the position the operator sets. Both the arm and balancers can rotate around the mast freely. The mounting allows operators to guide a torque tool rather than lift its whole weight, and the arm absorbs the torque reactions, further reducing the risk of strain and injury. The method of movement of the arm itself is what differentiates torque arm types. 

Telescoping arms allow their users to adjust the length of the arm in relation to its mounting mast. Given the full 360 degree rotation around the mast, these torque arms can fulfill most simple fastening operations quickly and easily. There are two types of telescoping torque arms: the traditional sort where the structure of the arm is made of tubes of two slightly different sizes, and the smaller one in which the tube slides in and out of the larger as needed to reach the length the operator desires.  

Linear torque arms expand and contract the radius the tool makes in a similar manner, but they use a different mechanism. Here, a mount glides along one or more structural tubes for smoother, steadier movement. 


Articulated torque arms have an elbow-like joint that gives these torque arms a second rotational axis which enables a greater degree of motion and motion control. At assembly stations with screw presenters or counters, these articulated torque arms provide easy movement of a tool from the presenter to the joint. Regardless of type, torque arms provide a greater degree of control over fastening, helping to prevent cross threading and side loading. 

Positioning Torque Arms

In many assemblies, tightening fasteners in the correct sequence is what ensures the reliability of the joint. Position control torque arms are designed for assembly lines with sequential fastening. They reduce the risks of improper fastening through the use of a position-control system (posi-control device). It consists of a torque arm equipped with an encoder and the posi-control device itself. 

A torque tool is mounted to the torque arm in the usual manner. The posi-control device is then set to the programming mode, and the tool runs down the fasteners in the proper sequence. The encoder sends arm positioning data to the posi-control device where it saves the data and the time it took to complete the rundown. During subsequent fastening with the positioning torque arm, the posi-control device will not clear a sequence unless it has been completed within the set parameters. It’s like having a quality control inspector at every posi-control equipped station. 

 

What Types of Torque Tools Work With Torque Arms?

With the right torque arm tool clamps, nearly any type of power assembly torque tool is compatible with a torque arm. Air screwdrivers, pulse tools, and DC control tools are all compatible with torque control arms regardless of whether their form factor is inline, right-angle, or pistol grip. Whether you’re working in heavy industrial manufacturing with pulse tools or assembling hard drive cases with electric torque screwdrivers, torque arms take the stress and strain off the hands, elbows, and shoulders of your employees.

Ergonomic assembly boosts productivity and is vitally important for your employees’ long-term health. By taking the fatigue out of fastening, torque arms allow your employees to focus on fastening in the correct sequence, at the correct torque setting, and with proper positioning. Torque arms improve precision and the quality and reliability of your products while allowing you to take better care of your employees. Ergonomic torque arms are a basic tool on the modern assembly line, and their purchase and setup should be a priority for anyone developing a productive manufacturing environment.


Mountz, Inc. provides torque arms and the tools to equip them for any assembly line or manufacturing facility. To find out how Mountz can deliver the precision your assembly operations demand, shop our store. Contact us anytime to ask a question. To inquire about price, request a quote. If you’d like to see our equipment in person, schedule an appointment. To get the latest torque-related news, follow us on LinkedIn.