This standard specifies the requirements for ferrule type couplings for tube with outside diameter from 4 mm to 42 mm used in oil-hydraulic systems. For the purpose of this standard, the definitions given in IS 10416 shall apply. ... On tightening, the force exerted uniformly makes the ferrule to bite onto the tube.

How do I choose a ferrule size?

If two AWG wires of the same size are being used, then the correct ferrule size can be determined by increasing the total wire size by three steps. For example, two 20 AWG wires (cross sectional area of 0.519mm2 each) are equivalent to a single 17 AWG/1.04mm2, so a 1.5mm2 capacity ferrule should be specified.

Are ferrules required for UL?

Ferrules have been used in applications for many years in Europe, and is required in most control panel applications. Ferrules standards started with DIN and was adopted by CAS in 2004. UL then allowed for the use of ferrules in accordance with UL-508A.