Synopsis of precess Routing: DIN high precision cold drawn NBK seamless steel tube is used as the tube to be phosphated, the phosphated is realized with the imported chemical fluid to form form a black protected film, the antirust oil is absorbed by the means of the micro pore on the film to prevent from the rust and two caps are sealed at two ends of the tube to prevent from the dust.
Main Feature: Bright black and the color is evenly distributed on the surface of tube and has good propery of antirust.
Main Application: Used in hydraulic system, nested card connector (pipe joints) with matching, it is one of our mainly export products. 
Specification: outer diameter Φ4mm-30mm, wall thickness 0.5mm-5mm, which can be customized according to the requirements of clients. The length is to length 6m(except for customization).