Torque for SERTO unions

It is customary in nearly all areas of the metal-working trade and industry to mount screws and nuts using torque wrenches in order to warrant a connection which is as safe and tight as possible. Minimum and maximum tightening torques are therefore indicated for all important applications.

We are frequently asked by customers what the recommended torque details for SERTO unions is. But the unique compression ferrule system from SERTO does not necessitate such information. On the contrary, SERTO unions canbe mounted safely and tightly without any additional accessories such as torque wrenches.

Why no torque details?

Under normal conditions, the torque depends on many different factors. Alone the tube quality (soft or semi-hard tube, small or thick wall thickness) or the production tolerances of the individual components can lead to significant deviations. SERTO has done extensive testing and has found that the measured tightening torques can differ by far more than 100%.

For repeated applications, in which the working conditions are always exactly the same (particularly industrial applications with large quantities), we can draw up torque recommendations in laboratory tests if all the parameters are known.

The secret lies in the design

For the compression ferrule unions from SERTO, which can be dismounted radially, the construction of the nut/compression ferrule combination was designed so that a truly leak-proof and safe connection can be achieved with the rotations indicated in our assembly instructions*. For soft or thin-walled tubes, stiffener sleeves provide the necessary support. Torque information and the supplementary tools are therefore redundant.

SERTO has been using this simple and reliable system with success for over sixty years. For industrial applications, SERTO also offers pre-assembly tools, which enable fast and automatic pressing.

Questions? Our specialists are glad to provide you with information or a practical demonstration.