Black rectangular tubes
Black square tube is a name for square pipe and rectangular pipe. It is made of strip steel after process treatment. In general, strip steel is unballed, leveled, crimped and welded into a round tube, which is rolled into a square tube and then cut to the required length.
Black square tube is also known as square and rectangular cold-formed hollow section steel, referred to as black square tube and black rectangular tube, code names are F and J, respectively. Widely used in machinery manufacturing, construction, metallurgy industry, agricultural vehicles, agricultural greenhouses, automobile industry, railway, highway guardrail, container frame, furniture, decoration and steel structure, etc.
GB/T6728-2017 "Cold-formed Hollow Section Steel for Structure"
The production specification
Mechanical equipment, solar energy equipment, steel structure, automobile parts, bridge piles, guardrail, ship internal structure.
The production process
Transportation and storage
Transportation: the steel pipe should be carefully handled during transportation, and is strictly prohibited from throwing, falling, dragging and violent impact to avoid deformity, which will affect the use and appearance quality of the steel pipe;
Storage: in the storage process is strictly prohibited to contact acid and alkaline substances, so as to avoid corrosion of the steel pipe. In the storage process, the steel pipe can not directly contact the ground, but should be padded with sleepers, try not to rain, in case of rust.