Applications:

High Precision Cold Rolled Seamless Steel Tube is used in automotive industry, and in the occasion where the high accuracy, brightness, cleanness of the tube are required.

Main Features：

1. Inner and outer walls of tube have high accuracy.
2. Excellent brightness.
3. No oxidization after heat treatment
4. High cleanness inside tube.

Quality Standards:

1. DIN 2391 Seamless Precison Steel Tubes
2. BS6323 Specification for Seamless and Welded Steel Tubes for Automobile, Mechanical and General Engineering Purposes
3. ASTM A519 Standard Specification for Seamless Carbon and Alloy Steel Mechanical Tubing

Steel Grades:

1. DIN Standard: St35, St52
2. BS Standard: CFS 4, CFS 5, CFS 10
3. ASTM Standard: 1020, 1045, 4130

Chemical Composition(%):

Grade	C	Si	Mn	P	S	Cr	Mo
St 35 (DIN1.0308)	0.17 max	0.35 max	0.40 min	0.025 max	0.025 max	/	/
St 52 (DIN1.0580)	0.22 max	0.55 max	1.60 max	0.025 max	0.025 max	/	/
CFS 4	0.25 max	0.35 max	1.20 max	0.050 max	0.050 max	/	/
CFS 5	0.23 max	0.50 max	1.50 max	0.050 max	0.050 max	/	/
CFS 10	0.26 max	0.35 max	0.80 max	0.050 max	0.050 max	0.80-1.20	0.15-0.30
1020	0.18-0.25	/	0.30-0.60	0.040 max	0.050 max	/	/
1045	0.43-0.50	/	0.60-0.90	0.040 max	0.050 max	/	/
4130	0.28-0.33	0.15-0.35	0.40-0.60	0.040 max	0.040 max	0.80-1.10	0.15-0.25

Size Range:

1. Outer Diameter: 5mm-220mm
2. Wall Thickness: 0.5mm-25mm

Delivery Conditions:

1. +C (BK) Hard. No final treatment after final cold rolling.
2. +LC (BKW) Soft. Final heat treatment is followed by a suitable drawing pass (limited reduction of area).
3. +SR (BKS) Stress Relieved. After final cold rolled, the tubes are stress relieved in a controlled atmosphere.
4. +A (GBK) Annealed. After final cold rolled, the tubes are annealed in a controlled atmosphere.
5. +N (NBK) Normalized. After final cold rolled, the tubes are normalized in a controlled atmosphere.

Mechanical Properties( T=20°C if not differently stated ):

Grades	Delivery Conditions	Tensile Strength Rm (Mpa)	Yield Strength R2 (Mpa)	Elongation in the longitudinal direction Al (%)
St 35	+C (BK)	480 min	/	6 min
St 35	+LC (BKW)	420 min	/	10 min
St 35	+SR (BKS)	420 min	315 min	14 min
St 35	+A (GBK)	315 min	/	25 min
St 35	+N (NBK)	340-470	235 min	25 min
St 52	+C (BK)	640 min	/	4 min
St 52	+LC (BKW)	580 min	/	7 min
St 52	+SR (BKS)	580 min	420 min	10 min
St 52	+A (GBK)	490 min	/	22 min
St 52	+N (NBK)	490-630	355 min	22 min
E235	+C (BK)	390 min	/	7 min
E235	+A (GBK)	315 min	/	25 min
E235	+N (NBK)	340-480	235 min	25 min
E355	+C (BK)	540 min	/	5 min
E355	+A (GBK)	450 min	/	22 min
E355	+N (NBK)	3490-630	355 min	22 min

Package:

1. Bundle Packing.
2. Plain end or vanished as per customer’s request.
3. Wrapped in waterproof paper.
4. Sackcloth with several steel strips.
5. Pack in heavy tri-wall boxes.

Mill Test Certificate:

MTC is issued in accordance with EN 10204.