GB/T2101—89 (General provisions of steel inspection, packaging, marking and quality certificate); GB9787—88/GB9788—88 (hot rolled edge/unequal angle steel size, shape, weight and allowable deviation); JISG3192— 94 (shape, size, weight and tolerance of hot-rolled steel); DIN17100-80 (general structural steel quality standard); ГОСТ535-88 (general carbon steel technical conditions). According to the above standards, angle steel should be delivered in bundles, the number of bundles, the length of the bundle, etc. should comply with the regulations. Angle steel is generally delivered in bare form, and it is necessary to pay attention to moisture protection during transportation and storage. Slot Diffusers,Slot Air Diffuser,Slot Diffuser Grill,Ceiling Slot Diffuser Guangzhou Jointair Co., Ltd. , https://www.jointair.cn