DIN 2391 Precision cold drawn seamless steel tube

DIN 2391 applies to seamless precision steel tubes and in compliance with ISO/DIN 3304, those tube dimensions have been selected from the range of manufacture dimensions which are mainly used as design elements.

Notes: DIN 2391 Pipe Seamless Precision Steel Tubes

1. Steel grades: St 35, St 45, St 52

2. Length up to 9 m.

3. Outside Diameter : 10 - 260 mm

4. Wall Thickness: 0,5 - 25 mm

5. Delivery condition:BK ,BKW,BKS,GBK,NBK

6. DIN2391-1/EN10305-1

7. GB/T 3639 Cold drawn or cold rolled precision seamless steel tubes

8. GB/T 8713 inside precision seamless tubes for hydraulic pressure and pneumatic services

9. Application: For auto use, for machinery, for oil cylinder tube, auto shock reducer inner cylinder

Other applications:

Widely used in Hydraulic cylinder systems, automobiles, injection molding machine, hydraulic press tube, EVA foam hydraulic machinery, precision hydraulic steel pipe cutting machine, shoe-making machinery, hydraulic equipment, high pressure tubing, hydraulic tubing, card sets of joints, pipe joints, rubber machinery, forging machinery, casting machinery, engineering machinery, automotive high pressure steel pipe concrete pump, sanitation vehicle, car Industry, shipbuilding industry, metal processing, military, diesel engine, internal combustion engine, air compressor, construction machinery, agricultural and forestry machinery, etc

If tubes having the tolerances and are produced according to the technical conditions of deivery as specified in this Standard are to e used as pipelines, then the dimensions specified in DIN 2448 may from time to time be used. These tubes must be ordered according to quality grade C.

cold rolled cold drawn seamless steel tube hydraulic cylinder barrel precision steel tube

DIN 2391 Seamless Precision Steel Tubes Mechanical Properties (Mpa)

Grade	Material Number	Tensile Strength MPa or N/mm2		Remaks (Similar to JIS)
		Min Yield Point	Tensile Strength
St30Si	1.0211	-	400Min	(STKM11)
		-	355Min
		-	285Min
		215	295~420
St30Al	1.0212	-	400Min	(STKM11)
		-	355Min
		-	285Min
		215	295~420
St35	1.0308	-	440Min	(STC38)
		-	370Min
		-	315Min
		235	340~470
St45	1.0408	-	540Min	(STKM13)
		-	470Min
		-	390Min
		255	440~570
St52	1.0580	-	590Min	(STKM19)
		-	540Min
		-	490Min
		350	490~630

DIN 2391 Seamless Precision Steel Tubes Chemical composition(%)

Grade	Mfg. Process	Chemical composition(%)
		C	Si	Mn	P	S	Ni	Cr	Mo	Others	a
											b
											c
											d
St30Si	S	0.10Max	0.30Max	0.55Max	0.040Max	0.040Max	-	-	-	-	a
											b
											c
											d
St30A1	S	0.10Max	0.05Max	0.55Max	0.040Max	0.040Max	-	-	-	Al deoxydized	a
											b
											c
											d
St35	S	0.17Max	0.35Max	0.40Max	0.050Max	0.050Max	-	-	-	-	a
											b
											c
											d
St45	S	0.21Max	0.35Max	0.40Max	0.050Max	0.050Max	-	-	-	-	a
											b
											c
											d
St52	S	0.22Max	0.55Max	1.60Max	0.050Max	0.050Max	-	-	-	-	a
											b
											c
											d

Note: a: Cold-finished/hard b: Cold-finished/soft c: Annealed d: Normalized

Delivery status	Abbreviation	Description
Cold-finished/hard Cold drawn/Cold rolled	BK (+C)	No heat treatment after the last cold-forming process. The tubes therefore have only low deformability.
Cold-finished/soft Cold drawn/Cold rolled	BKW (+LC)	After the last heat treatment there is a light finishing pass (cold drawing) With proper subsequent processing.
Cold drawn and stress relieved	BKS(+SR)	After the final cold drawing process there is a stress relief heat treatment in a controlled atmosphere.
Annealed	GBK (+A)	After the final cold-forming process the tubes are annealed in a controlled atmosphere.
Normalized	NBK(+N)	After the final cold drawing operation the tubes are normalized in a controlled atmosphere.

EN 10305-1	Steel Tubes For Precision Applications-1: Seamless Cold Drawn Tubes	E215,E235,E355	20-260mm
EN 10305-4	Steel Tubes for precision Applications-4: Seamless Cold Drawn Tubes for Hydraulic mid Pneumatic Power Systems	E215,E235,E355	20-260mm