Standard: BS6323-4 Seamless and Welded steel tubes for automobile,mechanical and general engineering purposes
Part 4: Specific requirements for cold finished seamless steel tubes"
Applications: for Auto industry / for machinery use/mechanical and general engineering
purposes Size range: O.D.:6-280mm W.T.:1-30mm L:max12000mm
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Design
ation
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Chemical Compositions( ladel analysis)
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|
|
|
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C
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Si
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Mn
|
Pmax.
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Smax.
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Cr
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Mo
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|
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%
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%
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%
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%
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%
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%
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%
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CFS 3
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0.20 max.
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0.35 max.
|
0.90max.
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0.050
|
0.050
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__
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__
|
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CFS 3Aa
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0.20 max.
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0.10 to 0.35
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0.60 to 1.00
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0.050
|
0.050
|
__
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__
|
|
CFS 4
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0.25 max.
|
0.35 max.
|
1.20 max.
|
0.050
|
0.050
|
__
|
__
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|
CFS 5b
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0.23 max.
|
0.50 max.
|
1.50 max.
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0.050
|
0.050
|
__
|
__
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CFS 6
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0.30 to0.40
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0.35 max.
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0.50 to 0.90
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0.050
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0.050
|
__
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__
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CFS 7
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0.20 to 0.30
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0.35 max.
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1.20 to1.50
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0.050
|
0.050
|
__
|
__
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|
CFS 8d
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0.40 to 0.55
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0.35 max.
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0.50 to0.90
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0.050
|
0.050
|
__
|
__
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CFS 9
|
0.29max.
|
0.35 max.
|
1.50max.
|
0.050
|
0.050
|
__
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0.15 to0.25
|
|
CFS 10
|
0.26max.
|
0.35 max.
|
0.80max.
|
0.050
|
0.050
|
0.80 to1.20
|
0.15 to0.30
|
|
CFS 11
|
0.45max.
|
0.35 max.
|
1.00 max.
|
0.050
|
0.050
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0.80 to1.20
|
0.15 to0.30
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Desig
nation |
BKc (cold finished/hard)
|
BKWc(cold finished/soft )
|
GBK and GZF(annealed)
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NBK and NZF(normalized)
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Remin.
|
Rmmin.
|
Amin.
|
Remin.
|
Rmmin.
|
Amin.
|
Remin.
|
Rmmin
|
Amin.
|
Remin.
|
Rmmin.
|
Amin.
|
|
N/mm2
|
N/mm2
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%
|
N/mm2
|
N/mm2
|
%
|
N/mm2
|
N/mm2
|
%
|
N/mm2
|
N/mm2
|
%
|
|
CFS3
|
360
|
450
|
6
|
280
|
400
|
9
|
170
|
340
|
26
|
215
|
360
|
24
|
|
CFS3Aa
|
360
|
450
|
6
|
280
|
400
|
9
|
170
|
340
|
26
|
215
|
360
|
24
|
|
CFS4
|
415
|
520
|
5
|
315
|
450
|
8
|
200
|
400
|
24
|
235
|
410
|
22
|
|
CFS5b
|
480
|
600
|
4
|
385
|
550
|
6
|
__
|
__
|
__
|
340
|
490
|
20
|
|
CFS6
|
470
|
590
|
5
|
350
|
540
|
7
|
300
|
440
|
22
|
280
|
460
|
21
|
|
CFS7
|
560
|
700
|
4
|
460
|
650
|
7
|
__
|
__
|
__
|
__
|
__
|
__
|
|
CFS8d
|
575
|
720
|
4
|
470
|
670
|
6
|
300
|
510
|
20
|
340
|
540
|
18
|
|
CFS9
|
575
|
720
|
4
|
470
|
670
|
6
|
__
|
__
|
__
|
__
|
__
|
__
|
|
CFS10
|
575
|
720
|
4
|
470
|
670
|
6
|
__
|
__
|
__
|
__
|
__
|
__
|
|
CFS11
|
575
|
720
|
4
|
__
|
670
|
6
|
__
|
__
|
__
|
__
|
__
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__
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"NOTE Welding of tubes of grades 3,3A and 5 does not require special techniques but care should be taken and welding carried out in accordance with guidance given in the appropriate British Standard for welding,
e.g. BS 5135.The welding of other grades shown may require special techniques.
a Grade 3A shall be suitable for case hardening purposes.
b Grain refining elements may be added at the option of the manufacturer .
c If tubes in the BK and GKW condition are subsequently welded,brazed or heated the mechanical properties in the heat affected zone may be reduced to those given for the delivery condition GBK or NBK.
d Steel within the limits shown,but in accordance with the chemical composition of BS 970-1,may be supplied if agreed ate the time of order or enquiry."
