DIN hydraulic steel tubes utilize high-quality pipe blanks provided by Baosteel, and the production process strictly adheres to the ISO9001:2000 quality system standards. Advanced modern production and quality management techniques are employed to achieve precision in the steel tube quality process.

 

The DIN hydraulic steel tube is a seamless steel tube produced from steel ingots, pipe blanks, or steel bars, which undergo processes such as pickling, cold rolling, and cold drawing. Subsequently, advanced high-temperature heat treatment technology (NBK state) is applied to produce steel tubes with a bright, smooth, highly precise, and highly clean surface. The inner and outer walls exhibit no oxidation layer, high precision, and the mechanical properties allow bending at any angle. The steel tube can withstand high pressure, exhibits no deformation during cold bending, and meets requirements for expansion, flattening, pulling, and more. It maintains advantages such as no cracking during cold bending, no cracks, and no oxidation layer on the inner and outer walls.

 

 

The hydraulic phosphated steel tube is a seamless tube processed after precision cold drawing and subjected to oxygen-free annealing to eliminate surface and internal stress. It then undergoes phosphating rust prevention treatment. The product boasts high dimensional accuracy, good ductility, ease of processing into various shapes without reducing or flattening the tube section. The surface precision is high, and after oxygen-free annealing, the surface hardness is moderate, facilitating sleeve connection. The inner hole and surface, after phosphating rust prevention treatment, require no acid pickling and can be directly installed.

 

- Outer Diameter (D): 4mm-76mm

- Wall Thickness (S): 0.5mm-6.0mm

- Customization available according to customer requirements

- Length: Fixed length of 6 meters (excluding custom orders)

 

- NBK (Normalizing)

- GBK (Annealing)

- BKS (Stress Relief Annealing)

 

- Mainly ST35, ST37.4 (10#), ST45 (20#), ST55 (35#), ST52 (16Mn), etc.

Material	C (Carbon)	Si (Silicon)	Mn (Manganese)	P (Phosphorus)	S (Sulfur)	Tensile Strength (MPa)	Yield Strength (MPa)	Elongation (%)
ST35	0.17-0.24	0.15-0.35	0.40-0.80	≤ 0.025	≤ 0.025	480-620	≥ 235	≥ 25
ST37.4	0.17-0.24	0.15-0.35	0.40-0.80	≤ 0.025	≤ 0.025	350-480	≥ 235	≥ 25
ST45	0.42-0.50	0.17-0.37	0.50-0.80	≤ 0.025	≤ 0.025	580-780	≥ 355	≥ 20
ST55	0.50-0.60	0.17-0.37	0.50-0.80	≤ 0.025	≤ 0.025	680-880	≥ 420	≥ 15
ST52	0.22-0.55	≤ 0.55	1.60-2.00	≤ 0.040	≤ 0.040	520-690	≥ 355	≥ 21

 

- Phosphating treatment, galvanized (yellow zinc), white zinc

- Length: Within 6 meters

 

Using finished tubes of DIN2391/EN10305 high-precision precision hydraulic seamless steel tubes as the base tubes for phosphating, the steel tubes are subjected to internal and external wall phosphating using imported environmentally friendly phosphating solution. This process forms a black phosphating protective film, and rust preventive oil is absorbed through the micropores in the phosphating film for rust prevention. Both ends are sealed for dust prevention.

 

- Steel Tube Color: Black with brightness

- High surface color uniformity, strong consistency, aesthetically pleasing appearance, and excellent rust resistance

- Can fully replace imported seamless hydraulic steel tubes of the same standard

 

1. Fluid seamless steel tube: GB8163-99

2. Boiler seamless steel tube: GB3087-1999

3. High-pressure boiler seamless tube: GB5310-95 (ST45.8-Ⅲ type)

4. High-pressure fertilizer equipment seamless steel tube: GB6479-1999

5. Geological drilling seamless steel tube: YB235-70

6. Petroleum drilling seamless steel tube: YB528-65

7. Petroleum cracking seamless steel tube: GB9948-88

8. Special seamless tube for petroleum drill collar: YB691-70

9. Seamless steel tube for automobile half-axles: GB3088-1999

10. Seamless steel tube for ships: GB5312-1999

11. Cold-drawn cold-rolled precision seamless steel tube: GB3639-1999 Various alloy tubes: 16Mn, 27SiMn, 15CrMo, 35CrMo, 12CrMoV, 20G, 40Cr, 12Cr1MoV, 15CrMo

 

[(Outer Diameter - Wall Thickness) * Wall Thickness] * 0.02466 = kg/m (weight per meter)