Channel to channel groove-shaped strip of steel. Representation of its specifications, such as 120 * 53 * 5, indicating a height of 120 mm waist, legs, height 53 mm, 5 mm thick waist channel, known as the 12 # channel. waist high the same channel, if several different legs wide and thick waist, the model on the right plus abc be distinguished, such as 25a # 25b # 25c #, common market, for a type and b-type. Channel is mainly used for building structures, vehicle manufacturing, and other steel structures, channels are also often used in conjunction with the I-beam. In accordance with the theory of steel structures, it should be channel wing forces, that channel should be standing, rather than the tummy. GB Specification: Origin Length (m) 5 # Local Chang Fu Heli 6.3 # 6 together 68 local Chang Fu Chang Fu # local force 610 # 12 # Maanshan Maanshan Jiang Tian Jiang Tian 6/9 6/9 14 # AB Horse Steel Jiang Tian 6/9 16 # AB Maanshan Jiang Tian 6/9 18 # AB Maanshan Iron River Days 9 20 # AB Maanshan Jiang Tian 9/12 22 # AB Jiang Tian 12 25 # AB Maanshan Iron River days of sunshine Laiwu Steel 12 28 # AB Jiang days of sunshine Laiwu Steel 12 30 # AB Jiang Tian Rizhao Laiwu Steel 12 32 # AB Jiang Tian Rizhao Laiwu Steel 12 36 # AB Haicheng Laiwu Steel 12 40 # AB Haicheng Laiwu 12 I operated the GB channel for Maanshan, Jiang Tian, ??sunshine, Jinxi agent in Changzhou region, Maanshan Iron and Steel products within 5% tolerance, sunshine, Jinxi product tolerances within 5%, the material is Q235B, Jiang Tian, ??Haicheng, tolerance macro steel is 8% - 10%. GB groove 14 # from the start points A, B, B-type ratio in both legs high, thick waist type A, should more than 2mm, account management and sales. Protocol type channel? 10 # 9m? 12 # 9m? 14 # 9m? 16 # 9m? 18 # 9m? 20 # 6m / 9m? 22 # 9m / 12m? 25 # 9m / 12m? 28 # 9m / 12m? 30 # 9m / 12m or more of Tangshan Iron and Steel products, tolerances in 15% - about 30%, Paul material, can weigh sales, less management terms, there is a channel with a special tolerance of about 15%. Protocol Class light channel: 5 # --18 # (non-standard) 5 # 15kg 20 kg 25 kg 28 kg 6.3 # 15.5kg 20kg 25kg 30 kg 32kg 34kg 8 # 20kg 25kg 30kg 35kg 40kg 42kg 10 # 30kg???? 35 kg 40 kg 45kg 50kg 52kg? 12 # 40kg 45kg 50kg 55 kg 60kg 62kg? 14 # 45kg 50 kg 55kg 60kg 65kg 70 kg 75kg? 16 # 55kg 60kg 65kg 70 kg 75kg 80kg 85kg 88kg? 18 # 85kg 90kg 95kg 100kg 105kg? Above Tangshan Iron and Steel products, tolerances in 15% - ranging from 50% by weight of only estimates, made of Q235, length is 6m, weighing sales.