BS6323-6 Cold Finished Electric Resistance DOM Steel Tubes with BK , BKW ,GBK , GZF , NBK , NZF

Product Description

BS6323-6 DOM Steel Tubes Cold Finished Electric Resistance Welded Steel Tubes with BK , BKW , GBK , GZF , NBK , NZF

 

 

Standard: BS6323-6  Seamless and Welded Steel Tubes for Automobile,Mechanical and General Engineering Purposes                                        
Part 6: Specific requirements for cold finished electric resistance welded(including induction welded) steel tubes                        

                
Applications: for Auto industry / for machinery use/mechanical and general engineering purposes                
                                                          
Size range: O.D.:6-350mm     W.T.:1-35mm      L:max12000mm

 

Method of Manufacture:

The tubes are manufactured from flat rolled strip, longitudinally welded continuously by the passage of an electric current across the abutting edges without the addition of filler metal.

They are subsequently cold finished normally on both the inside and outside surfaces, where it is permissble to have both an adherent layer of residual lubricant originating from the drawing process and visible traces of the internal weld upset.

If phosphate or other residues are detrimental to subsequent processing, their removal shall be the subject of an agreement between the manufacturer and purchaser.

 

Delivery Condition:

The tubes are supplied in one of the following condition:

a. Cold finished/hard (cold finished as drawn) : BK

b. Cold finished/soft (lightly cold worked ):  BKW

c. Annealed: GBK

d. Annealed (including de-scaling): GZF

e. Normalized: NBK

f.  Normalized ( including de-scaling): NZF  

It is permissible for tubes supplied in the GBK and NBK conditions to be discoloured, but they shall be free from loose scale.

Where tubes, in the GBK condition are required bright annealed, this shall be the subject of an agreement between the purchaser and the manufactuer.

 

Testing:

Flattening test

Drift expanding test

Leak tightness test.   

 

 

Chemical Compositions and Mechanical Properties
Design ation	Chemical Compositions( ladle analysis)					Mechanical Properties
	C	Si	Mn	P	S	BKc  (cold finished/hard)			BKWc (cold finished/soft )			GBK and GZF                                 (annealed)			NBK and NZF                             (normalized)
	max.	max.	max.	max.	max.	Re       min.	Rm min.	A min.	Re       min.	Rm min.	A min.	Re min.	Rm min.	A min.	Re min.	Rm min.	A min.
	%	%	%	%	%	N/m m2	N/m m2	%	N/m m2	N/m m2	%	N/m m2	N/m m2	%	N/m m2	N/m m2	%
CEW1a	0.13	__	0.60	0.050	0.050	320	400	6	245	350	10	150	270	27	155	280	25
CEW2a	0.16	__	0.70	0.050	0.050	355	420	6	260	370	10	160	300	27	195	320	25
CEW3a	0.20	0.35	0.90	0.050	0.050	360	450	6	280	400	9	170	340	26	215	360	24
CEW4b	0.25	0.35	1.20	0.050	0.050	415	520	5	315	450	8	200	400	24	235	410	22
CEW5b	0.23	0.50	1.50	0.050	0.050	480	600	4	385	550	6	__	__	__	340	490	20

 

Tolerance on diameter
diameter		Tolerance
over	Up to and including
mm	mm	mm
	30	±0.10
30	50	±0.15
50	70	±0.20
70	90	±0.25
90	110	±0.30
110	130	±0.35
130	160	±0.45
160	190	±0.55
190	220	±0.65
220	250	±0.75

 

Tolerance on specified cut lengths
Specified cut length		Tolerance(mm)
over	up to and including
mm	mm	mm
	500	+	2
		-	0
500	2000	+	3
		-	0
2000	5000	+	5
		-	0
5000	7000	+	10
		-	0
7000	__	by agreement
NOTE Closer tolerances may be obtained by agreement between the purchaser and manufacturer.

 

 

Distance between platens for flattening test
Designation	Distance between platens
	%
CEW 1	66
CEW 2	75
CEW 3	85
CEW 4	85
CEW 5	85

 

Minimum expansion for drift expanding test
Designation	Expansion minimum for tube thickness
	Up to and including 4mm	Over 4 mm up to and including 8 mm
	%	%
CEW 1	12	8
CEW 2	12	8
CEW 3	10	6
CEW 4	8	5
CEW 5	8	5

 

Note: Special steel grade is also available, according to customer request.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

For Application of:

 

 

 

 

 

 

 

 

 

 

 

 

 

Publications referred to:

BS 3601

BS 3602

BS 3603

BS 3604

BS 3605

BS 4360

BS 4848

BS 4848-2

BS 5135

BS 6323

BS 6323-1 

BS 6363

ISO 4200