A leak proof seal is obtained through proper ferrule action as the ferrules are tightened onto the tubing via axial thrust provided by the nut. The front ferrule of these SS tubing fittings provides the leak proof seal, when the nut and ferrules are properly drawn up the specified number of turns. The rear ferrule grips the tubing preventing pull-off. The stainless-steel nuts are silver plated and a dry film lubricant is applied, reducing torque and ensuring proper sealing. Browse our selection of metal tube fittings below.