CNC Turned Brass, Aluminum and Stainless Steel Fittings

Fittings are turned from round or hex bar on CNC lathes; hex stock removes a milling step for wrench flats. Internal ports are drilled and bored, then threads are single-point cut or tapped depending on size and tolerance class. Sealing faces and O-ring grooves are finished with a light final pass to reach a smooth surface. Cross-drilled ports and side outlets are milled with live tooling in the same setup.

Free-cutting brass is the fastest material to machine and naturally resists water and air corrosion, making it a common choice for plumbing and pneumatics. Aluminum is lighter and cheaper but needs anodizing for durability and is less suited to high-pressure threads. Stainless 316 handles chemicals and marine environments; it costs more to cut. Finishes include nickel plating on brass, anodizing on aluminum, and passivation or polishing on stainless.

Threads are checked with go/no-go plug and ring gauges, sealing faces for surface roughness with a profilometer, and port positions on CMM at first article. Critical dimensions are inspected on every part before shipping, and material certificates are available on request. Typical applications are pneumatic adapters, hydraulic test ports, gas regulator bodies, coolant nozzles and instrument connections.