Specifications(mm): 20X20X2--200X200X25 Material: Q235,Q345,SS400,SS540,Q195,45# Place of Origin: China (Mainland) Brand Name Channel steel Material: Q235,Q345,SS400,SS540,Q195,45#Specifications(mm): 50X37X4.5X7.0--400X104X14.5X18length is 6m---12m.Standard: GB/T9787-1988,JIS G3192-1977