U-SHAPED STEEL BRACKET IS A KIND OF STEEL WITH A CROSS-SECTIONAL SHAPE LIKE THE ENGLISH LETTER "U".THE CROSS-SECTIONAL SHAPE,GEOMETRIC PARAMETERS AND MATERIALS OF U-SHAPED STEEL PRODUCT IN DIFFERENT COUNTRIES ARE DIFFERENT.AT PRESENT,THERE ARE FOUR TYPES OF U-SHAPED STEEL PRODUCTED IN CHINA:U18, U25, U29, AND U36.AMONG THEM, U18 AND U25 BELONG TO WAIST POSITIONING; U29 AND U36 BELONG TO EAR POSITIONING.THE U18 IS RARELY PRODUCTED DUE TO ITS LOW CARRYING CAPACITY.