20 Years of Experience in Seamless Steel Tube Production

DIN Black Phosphated Hydraulic Tube - Manufacturers DIN Black Phosphated Hydraulic Tube - Manufacturers

Carbon steel tube, NBK, Normalized, phosphated and oiled inside and outside.

  • Bright black
  • OD 4-89 mm
  • WT 0.5-7 MM.Length: 6000 MM or Customized
  • Carbon steel
  • Alloy steel
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  • Model: Round tube
  • Brand: SDY
  • Code: 02
  • Product Description
  • Production Process Advantages


Hydraulic pipe fittings suppliers

Synopsis of Process Routing: Cold drawn and bright NBK seamless steel tube is used as the tube to be phosphated.

The phosphated is realized with the imported chemical fluid to form a black film.

The antirust oil is absorbed by means of the micro pore on the film to prevent from the rust. The caps are covered at two ends of black phosphating steel tube to prevent from the dust.


Main Features: Color of steel tube: bright black color is homogeneously distributed on the tube surface. The hydraulic seamless tube has good property of antirust.


Main Application: Used in hydraulic system, shipment industry, nested card connector ( pipe joints ) with matching.

Main Material Mechanical Property:

The steel grades of raw material used in our company arc mainly ST35, ST37.4(10#), ST45(20#), ST55(35#), CK45(45#) ST52.4(16Mn) etc, produced by Shanghai Baosteel Group.

The steel tube produced by our company has excellent mechanical property and performance in process. The steel tube is able to withstand the high pressure, impact and particularly suitable for application of hydraulic machinery and automotive fabrication. The tube can be cold bent at any angle. No crack will occur after flaring and flattening for the industry, which the bending and forming is required in process.


Surface quality: The internal and external surfaces of tube must be clean without any oxidization, crack, fold, rolling fold, scar and laminar detect. The status ot inner and outer surfaces is the same as that of the process and heat treatment, but the depth of defects (e.g. scratch mark, bulge and concavity) is not allowed to exceed 0.025mm (such requirement is stricter than DIN2391 standard).

Packing against corrosion and transportation of tube: The stainless steel hydraulic cylinder tube was painted with antirust oil, covered with caps at two ends, packed with plastic film and linen or wooden case.

Note: Certificate of quality assurance of tube will be presented.

Our Certificate:

At the present time,SHENGDINGYUAN is equipment with the leading products line in China,and boasts of its quality guaranteen system and international quality in a complete set.Our corporation's products have been certified by ISO9000-2000 standard,the international quality management system,in 2006 and 2007 separetely.Meanwhile,we have nanaged production quality in an all-round way,in alignment waih ISO/TS16949:2002 standard.Our corporation has a professional team engaging in research,development design,as well as a standard laboratory ang testing center.Thanks to it,our production technologies have been continually optimized and improved,product quality steadily increased and market incessantly extended.Our quality policy:Guest comes first and systematic management,high quality and efficiency,eternal improvement.


1.Round Bar Cutting Equipment and Process 

Operation workers according to the production process card requirements set the length of the material debugging equipment, and then roll round steel to the automatic material transfer belt to cut off, according to the requirements of the process card cut enough quantity after the steel cable hoisting to the next process-hot piercing.


2.Hot Piercing Equipment and Process

The operation staff hoist the cut off round steel to the automatic feeding place of the hot piercing equipment, and automatically feed the material into the heating furnace through the roller and conveyor belt according to the set value. After heating to a certain temperature, the round steel enters the perforation machining channel through the transmission belt, and then moves to the punch machine through the conveyor belt after perforation, punching one end and returns to the material rack for natural cooling and hoisting.


3.Cold Drawn Equipment and Process

According to the requirements of the production process card, The operation staff drawing the semi-finished product and checked by the technician to see if it meets the requirements of the process card. After once or twice cold drawing, the semi-finished product needs intermediate annealing - surface treatment (pickling - phosphating - saponification)- rolling head (pressing head is convenient for cold drawing after clamping die cold drawing)- medium cutting (cutting according to process card requirements and then cold drawing again).

Cold drawing is a processing technology of materials. For metal materials, cold drawing refers to drawing in order to achieve a certain shape and certain mechanical properties, while the material is at room temperature. Cold-drawn products have the advantages of high dimensional accuracy and good surface finish compared with thermoforming.



4.Cold Drawn Procss's Oxygen Annealing Equipment and Process

The operation staff carries on the intermediate annealing heat treatment to the semi-finished product in the drawing process according to the production process card requirements, and carries on the surface treatment (pickling, phosphating, saponification) process after the natural cooling.


5.Surface Treatment (pickling, phosphating, saponification)

After intermediate annealing (oxygen annealing) heat treatment, the semi-finished product is transferred to the surface treatment workshop for pickling-phosphating- saponification.

6.Bright Annealing Furnace and Process

The operator arranges the process card requirements and operation specifications for the semi-finished products which are cold drawn to the outer diameter of the finished product specifications. After the wire is bundled in batches, one end is blocked with asbestos, and placed on the transmission belt at the set speed into the furnace for heating and heat preservation for a period of time.


7.Semi-finished Products Processing Workshop

Semi-finhsed prodecuts processing workshop director according to production plan sheet requirements and process card instructions to arrange each pass straightening (through array up and down stick roller press, ensure steel pipe straightness)- gauge cutting head and tail (according to customer required length cut finished product)- Eddy current inspection (monitoring surface defects, defects will automatically alarm identification)- Manual inspection (according to production process card requirements for steel pipe wall thickness (wall thickness micrometer), outer diameter and inner diameter (Vernier caliper, clip gauge), straightness (put on marble inspection table plug ruler), inside and outside surface (in light photo condition check steel pipe inside and outside surface defects or bruises)- Packaging (according to production plan sheet) and process card requirements).



8.Product Warehouse


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