When it comes to securing your hydraulic fittings, tight is tight right? Not exactly. If the recommendation is to "turn" not "torque" to assemble the connection you're best bet is to follow those instructions. Understanding the difference between a torque and a turn means you’ll never be in doubt when assembling or reassembling hydraulic fitting connections in your system, keeping it leak-free for years to come.
In the case of torque, a calculation is used to determine how much torque hydraulic threads can handle without being damaged. Going over or under the recommended torque can lead to leaks. When you tighten a fitting, in some circumstances you’re actually deforming the metal, which can damage threads and sometimes the fitting, making it unfit for re-use. In other circumstances, an O-ring could be pushed down into the female threads, compromising the seal of the connection.
When a turning method is recommended, you will see a very low number in the tightening recommendations. Generally that number will be no higher than 3. These numbers are linked to two types of turning methods that do not require a torque wrench.
Torque is a measurement of force. In the case of hydraulic fittings, it’s the rotational force used when tightening, generally using a torque wrench. Torque is important because it helps you know how tight your fitting connection needs to be when your system is running at higher pressures.