... BK, BKS, GBK, NBK, Stress Relief, Normalizing, Spheroidize Anneal, Annealing, OD: 1/4"-12" Executive Tube Standard: ... , NBK, Stress Relief, Normalizing, Spheroidize Anneal, Annealing, Bright Annealing, Normalized, Quenched and Tempered, Solution Annealing, etc; 4) ... , Hydrostatic Test; 9) Main Applications: Boiler and Heat Exchanger, Hydraulic and Petrochemical Purpose, etc. Commercial Information: 1) ...