Start choosing a nutrunner with the required torque range

The first parameter to establish is the torque required for the joints that the nutrunner will handle. What counts is the tool's entire working range, that is, both its lower and its upper limit.

If a single nutrunner is to work on several types of joints, its range must cover all of the values used. For example, for work carried out at a torque of 500 to 2000 Nm, the 360-2500 Nm models are a suitable starting point. A 280-1200 Nm nutrunner will not handle the upper value, while choosing a 1024-10000 Nm unit would rule out work at the lower required torques.

The electric Juwel models available in this category come in six basic ranges:

The required torque therefore lets you quickly narrow down the number of possible models. The next step is to choose the design of the nutrunner and to check the conditions at the place where the joint will be made.

TES or TEWS? Choose the design to suit the place of work

For the same basic torque ranges, Juwel offers two designs of electric nutrunners. The TES series has a straight layout, while the TEWS series uses an angle design.

TES is the natural choice for joints that can be approached freely with the tool in line with the axis. TEWS was designed for work in more confined spaces, where the position of the drive relative to the drive square affects whether the whole unit can be positioned.

The difference is well illustrated by the dimensions of the corresponding models. For the 280-1200 Nm range, the manufacturer gives a dimension H of 540 mm for the TES-104/105 and 275 mm for the angle TEWS-104/105. For the 1024-10000 Nm range, it is 680 mm for the TES-904/905 and 390 mm for the TEWS-904/905 respectively. In tight machine enclosures, steel structures or installations, such a difference can decide whether the tool can be positioned correctly on the joint.

In both series, the drive can rotate through 360°, which allows the drive section to be set in a convenient position. The fundamental difference between TES and TEWS therefore remains the geometry of the entire nutrunner.

If the space around the joint is limited, before choosing a model it is worth knowing not only the required torque, but also how much room is available around the bolt and where the tool is expected to be positioned.

Standard or Heavy Duty? Take the intensity of use into account

Many TES and TEWS models come with two gearbox versions. This is already visible in names such as TES-244/245 or TEWS-604/605. These are variants intended for different operating conditions.

The standard version is intended for applications in which the tool does not work constantly under heavy load. Heavy Duty gearboxes have additional bearings and a modular housing design that increases resistance to wear during intensive, regular use.

For example, the TES-244 is the standard variant, and the TES-245 is the Heavy Duty version of the same 360-2500 Nm torque range. The same division applies to the corresponding TEWS angle models.

For occasional or one-off jobs, the standard version may be sufficient. For production, maintenance or regularly repeated tightening operations, it is also worth taking into account the frequency of cycles, the tool's running time and the mechanical and thermal loads involved.

This is an important criterion especially when two variants have the same torque range. The Nm value alone does not then explain the difference between them.

Check the drive and the sockets you use

As the torque range increases, the size of the drive also changes.

The TES-84 and TEWS-84 models are available with a 3/4" or 1" drive. In the 280-1200 Nm and 360-2500 Nm ranges, a 1" drive is used. The 360-3500 Nm, 816-6000 Nm and 1024-10000 Nm models use a 1 1/2" drive.

Before choosing a nutrunner, therefore, check the size of the sockets used on the joints you will be handling. This is particularly important when moving between adjacent ranges. For example, the 360-2500 Nm models use a 1" drive, while at 360-3500 Nm it is already 1 1/2".

If the tool is to go to an existing workstation equipped with a particular set of sockets, drive compatibility should be verified before ordering.

For series work, compare speed as well

Torque and design determine whether a nutrunner can be used on a particular joint. With a large number of repetitive operations, speed also becomes important.

In the models we offer, the no-load speed changes with the range of the tool. The TES-84 and TEWS-84 reach 16 rpm, the 280-1200 Nm models 14 rpm, and in the largest range offered, 1024-10000 Nm, it is 2.5 rpm.

When tightening individual joints only occasionally, this difference may be of little significance. At a workstation where the tool performs many consecutive cycles, it already affects the time needed to complete the work. If several models cover the required torque, speed is one of the parameters worth using to narrow down the choice further.

Plan space for the reaction arm

The high torque generated by the nutrunner requires the reaction torque to be absorbed. This is why TES and TEWS models are equipped with a reaction arm.

Before choosing a unit, check where the arm will be able to be stably supported during tightening. The layout of neighboring bolts, the structural elements around the joint and the amount of available space all matter. In practice, the geometry of the support can be just as important as the geometry of the nutrunner itself.

A standard reaction arm is included in the set. If its shape does not suit a particular workstation, a custom reaction arm made specifically to the user's individual needs is also available for Juwel nutrunners. There is also the option of buying a ring that lets you make your own reaction arm.

For unusual structures, it is worth establishing the method of support before choosing the final model, rather than adapting the workstation only after the tool has been purchased.

How is torque controlled in TES and TEWS nutrunners?

Juwel TES and TEWS models allow you to choose from 200 torque settings. When the set value is reached, the system cuts off the drive. The manufacturer declares a torque accuracy of +/-3.5% for the same type of joint.

Each nutrunner is supplied with an individual calibration certificate and a torque table. The tools can work in both directions, so in addition to controlled tightening they can also be used to loosen previously made joints.

At high torques, the stress release function after tightening is also important. When the set value is reached, the drive makes a small movement in the opposite direction, which makes it easier to remove the socket and the tool from the joint.

It is precisely the ability to set a specific value, finish tightening automatically and document the tool's characteristics that distinguishes this group of devices from nutrunners intended mainly for fast assembly without torque control at this level.

When to choose mains power, and when a different multipliers?

TES and TEWS nutrunners are a solution for workstations where mains power can be provided. The cord eliminates the need to manage batteries and works especially well for work carried out in a fixed or predictable location.

If the tool is to change workstations often, work in the field or in places without convenient access to power, it is worth comparing it with the cordless Juwel equivalents. Available are the straight cordless TQS multipliers and the angle cordless TQWS multipliers.

In plants that use a compressed air installation, pneumatic wrenches are an alternative. The choice of drive source should therefore be considered together with the place of work, the mobility of the tool and the infrastructure available at the workstation.