BS6323-6 CW1 CW2 CW3 CW4 CW5 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, longintudinally 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 (cod 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.   

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