The ferrule absorbs vibration and thermal expansion, drastically reducing leakage and fatigue failures.
"Serial number 88-Delta-Alpha," Elias whispered into his headset. "Surface finish looks like glass. Mating surfaces are pristine." sae-as33514
Flareless fittings are often preferred in aerospace because they don't require the extra material needed to form a flare, helping reduce the overall weight of the hydraulic system. Vibration Resistance: sae-as33514