The Parker A-Lok NU-B series compression tube fitting nut is made of brass, and is for use with a ferrule set to connect tubing to a fitting. This nut, when used with a brass twin ferrule compression fitting set (sold separately), helps provide a leak-resistant seal in high-pressure applications. It is made of brass for corrosion resistance, ductility at high temperatures, and low magnetic permeability.

Pipe and tube fittings are components used for connecting, terminating, controlling flow, and changing the direction of piping in many different industries. Compression fittings do not require tools or sealants, and are useful in installations where a heat source, such as a soldering torch, is prohibited. When purchasing fittings, consider the application, as this will affect material type, shape, size, and required durability. Fittings are available threaded or unthreaded, in many shapes, styles, sizes, and schedules (pipe wall thickness).

Parker Hannifin manufactures electromechanical, hydraulic, and pneumatic motion technologies and systems for fluid handling, filtration, sealing and shielding, climate control, process control, and aerospace applications. The company, founded in 1918, is headquartered in Cleveland, OH.