Standard: BS6323-4 Seamless and Welded steel tubes for automobile,mechanical and general engineering purposes
Applications: for Auto industry / for machinery use/mechanical and general engineering purposes Size range: O.D.:6-156mm W.T.:1-20mm L:max12000mm
Method of manufacture:
The tubes are manufactured by a seamless process and shall be cold finished
It is permissible for cold finished tubes to have on internal and external surfaces an adherent layer of residual to subsequent processing, then their removal shall be the subject of an agreement between the manufacturer and the purchaser.
The tubes are supplied in one of the following condition:
Cold finished/hard (cold finished as drawn) : BK
Cold finished/soft (lightly cold worked ): BKW
Annealed (including de-scaling): GZF
Normalized ( including de-scaling): NZF
It is permissible for tubes supplied in the GBK and NBK condition to be discoloured, but tubes shall be free from loose scale.