Cold-drawn or cold-rolled precision seamless steel tubes
1 Scope
This standard specifies the classification, symbols, dimensions, appearance, weight, limit deviations, technical requirements, test methods, inspection rules, packaging, marking and certification for cold-drawn or cold-rolled precision seamless steel tubes.
This standard is applicable to the cold-drawn or cold-rolled precision seamless steel tubes requiring special dimension precision and high surface quality for manufacturing mechanical structures, hydraulic equipment and automobile appliance.
2 References
The following standards contain provisions which, through reference in this standard, constitute provisions of this standard. At time of publication, the editions indicated were valid. All the standards will be modified, however, parties to agreements based on this standard shall investigate the possibility of applying the most recent editions of the documents indicated below
GB 222-1984 Method of sampling steel for determination of chemical composition and permissible variations for product analysis
GB/T 223.5-1997 Methods for chemical analysis of iron, steel and alloy The reduced molybdosilicate spectrophotometric method for the determination of acid-soluble silicon content
GB/T 223.12-1991 Methods for chemical analysis of iron, steel and alloy The sodium carbonate separation-diphenyl carbazide photometric method for the determination of chromium content
GB/T 223.23-1994 Methods for chemical analysis of iron, steel and alloy The dimethylglyoxime spectrophotometric method for the determination of nickel content
GB/T 223.27-1994 Methods for chemical analysis of iron, steel and alloy The thiocyanate-butyl acetate extraction spectrophotometric method for the determination of molybdenum content
GB/T 223.59-1987 Methods for chemical analysis of iron, steel and alloy; The reduced molybdoantimonyl phosphoric acid photometric method for the determination of phosphorus content
GB/T 223.63-1988 Methods for chemical analysis of iron, steel and alloy; The sodium (potassium) periodate photometric method for the determination of manganese content
GB/T 223.68-1997 Methods for chemical analysis of iron, steel and alloy The potassium iodate titration method after combustion in the pipe furnace for the determination of sulfur content
GB/T 223.69-1997 Methods for chemical analysis of iron, steel and alloy The gas- volumetric method after combustion in the pipe furnace for the determination of carbon content
By the final supply conditions of steel tubes (symbols are in brackets): cold finished/hard (BK), cold finished/soft (BKW), cold finished and stress-relieved (BKS), annealed (GBK) and normalized (NBK).
4 Dimension, appearance, mass and limit deviations
4.1 Diameter and wall thickness
4.1.1 The diameter and wall thickness of steel tubes shall meet those specified in Table 1.
1 Scope 2 References 3 Classifications and symbols 4 Dimension, appearance, mass and limit deviations 5 Technical requirements 6 Test methods 7 Inspection rules 8 Packaging, marking and certification
