DIN 1629 Structural Seamless Tube

DIN 1629: Seamless Circular Unalloyed Steel Tubes Subject to Special Requirements

Standard: DIN 1629
JST can provide different grades of structural steel pipes, such as St37.0, St44.0, St52.0, and so on.

Applications

• DIN 1629 structural steel tube is applicable for manufacturing pipelines, containers, equipment, pipe fittings and steel structures.
• These structural steel pipes are predominantly used in construction of chemical plants, vessels, pipeworks and for general mechanical engineering purposes.

Size Range The size range of DIN 1629 structural steel tube is as follows:

• Outer dimension is from 6.0 mm to 219.0 mm.
• Wall thickness of this structural steel pipe ranges from 1.0 mm to 30 mm.
• The maximum length is 12000 mm.

Advantages of DIN 1629 Structural Steel Tube

• JST advanced rolling technology makes the quality of pipes reach the standard level. Under the advanced rolling technology, our structural steel pipes are much purer and have smaller tolerance range than that produced by other manufacturers
• JST configures micro oxidation and non-oxidation heat treatment furnace that can provide the required thermal treatment temperature for structural steel tubes. The temperature difference is controlled within 5℃. After heat treatment, there is no oxidation layer on the pipe. The structural steel pipe acquires higher surface quality and more stable performance. Thus the usage life is improved.
• We possess multiple inspection machines for testing the inside and outside surface quality of pipes.
• JST configures UNICORN ultrasonic joint inspection machine, automatic ultrasonic inspection machine and magnetic flux leakage inspection machine to check the obvious defects on the surface of structural steel tubes or structural steel pipes. We also own professional surface inspectors who gain the relevant appropriate qualifications. Our company provides regular training and carries out artificial inspection for the inside and outside defects of pipes to guarantee stable performance of pipes.
• Under the JST advanced rolling technology, the allowable deviation of DIN 1629 structural steel tube is controlled within the standard range, even smaller than the standard range.

Packaging of DIN 1629 Structural Steel Pipe Customers can choose bare, bundles, crates or crate protection at the both sides of tubes. We can also package products as per customers' requirements

Parameters of DIN 1629 Structural Steel Tube

1. Chemical Composition of DIN 1629 Structural Steel Pipe

Standard	Grade	Chemical Composition Limits (%)
		C	Si	Mn	P	S	Cr	Mo
DIN1629	St37.0	≤ 0.17	/	/	≤ 0.040	≤ 0.040	/	/
	St44.0	≤ 0.21	/	/	≤ 0.040	≤ 0.040	/	/
	St52.0	≤ 0.22	≤ 0.55	≤ 1.70	≤ 0.040	≤ 0.040	/	/

2. Mechanical Properties of DIN 1629 Structural Steel Tube

Standard	Grade	Tensile Strength (MPa)	Yield Strength (MPa)	Elongation (%)
DIN1629	St37.0	350-480	≥ 235	≥ 25
	St44.0	420-550	≥ 255	≥ 21
	St52.0	500-650	≥ 270	≥ 21

Other Parameters

1. Max. Working Pressure and Temperature of St37.0, St44.0 and St52.0

	Max. Working Pressure	Max. Working Temperature (°C)	Provided Document
D ≤ 219.1	64	300	DIN 50049
219.1< D ≤ 660	25	300
D > 660	16	300

Note: a. 1bar=0.1MPa

b. DIN50049 is Germany metal product inspection file type standard.  

2. Outer Diameter Deviation of Structural Steel Pipe

Outer Diameter (mm)	Outside Diameter Deviation
	Pipe Body and Pipe End	Pipe End: It needs to be specially dealed.
≤ 100	±1%D或±0.5mm	± 0.4 mm
100 < D ≤ 200	±1%D	± 0.5 % D
> 200	±1%D	± 0.6% D

Note: a. Pipe end refers to the place within 100 mm to the pipe port.

b. The allowable deviation may involve the inside diameter and cause the allowable deviation of wall thickness. Thus we should take the inside diameter into consideration when formulating the agreement content.  

3. DIN1629 Wall Thickness Allowable Deviation

D ≤ 130 mm			130 < D ≤ 320 mm			320 < D ≤ 660 mm
S
≤ 2Sn	2Sn < S ≤ 4Sn	> 4Sn	≤ 0.05D	0.05D < S ≤ 0.11D	>0.11D	≤ 0.05D	0.05D < S ≤ 0.09D	> 0.09D
+15% -10%	+12.5% -10%	± 9%	+17.5% -12.5%	± 12.5%	±10%	+20% -15%	+15% -12.5%	+12.5% -10%

Note: Sn is the length deviation of DIN1629 with standard thickness regulated in DIN2448.  

4. Inspection Item of Structural Steel Tube

No.	Inspection Item	Inspection Range	Inspection Responsibility	Pipe Billet Inspection Documents
1	Tensile Test	Choose one sample from a batch of steel pipes.	Determined in Consultation	DIN50049-3.1A DIN50049-3.1B DIN50049-3.2C
2	Flattening Test	The wall thickness of one end of regulated steel pipe sample should not exceed 40 mm. It does flattening test.	Determined in Consultation
3	Compactness Test	Test each steel pipe.	Manufacturer
4	Surface Test	Test each steel pipe.	Determined in Consultation
5	Diameter Test	Test each steel pipe.	Determined in Consultation
6	Product Analysis	Determined in Consultation	Manufacturer

5. Allowable Shape Deviation of Structural Steel Pipe

Roundness	The outside roundness should be controlled within the allowable deviation.
Straightness	It must be straight in visual inspection. If there is any special requirement, we make according to users' requirements.

6. Tube End Polishing

1. Tube end should be vertical to the pipe central axis after cutting. There is no burr on the pipe end.

2. According to agreement, we use steel pipes with the wall thickness of 3.2 mm to do polishing.

3. The angle of side channel is 30°. The surface thickness of steel pipe end is1.6 mm (±0.8 mm).

7. Allowable Weight Deviation of Structural Steel Tube

Weight Deviation of Each Steel Pipe	+12%, -8%
Weight Deviation of a Batch of Steel Pipes with the Weight of More than 10 Tons	=10%, -5%

Note: DIN2448 regulated the weight of steel pipes per unit of length.

Founded in 1984, Jiangyin Changjiang Steel Tube Making Factory is a professional manufacturer of seamless steel tubes and various special pipes. Our products mainly cover casing, tubing or oil pipe, line pipe, drill pipe, high pressure boiler pipe, marine pipe, cylinder tube, hydraulic prop tube, fluid pipe, structural steel pipe, etc. They have passed API 5CT, API 5L, API 5DP, CCS, LR, DNV, ABS, NK, BV, GL, PED, SGS, ISO9001:2000 and ISO14001:2004 certifications. Our structural steel tubes have won widespread praise and recognition by customers.