The production process of black steel pipe and hot rolled pipe is similar, the difference is that the hot rolled pipes needs sizing and straightening. The black steel pipe don’t need it.
One of main differences between black annealed steel pipe and hot rolled steel pipe is raw materials. The hot rolled pipe’s raw material is hot rolled strip and the annealed pipe’s raw material is cold rolled annealed steel strip.
Beside the different of raw material, the application is also different. The annealed pipe widely used on furniture, such as table, chair. For the hot rolled steel pipes, one of main application is basic building structure, such as highway guardrail, scaffolding, greenhouse fence, Sports Equipment and pipeline and so on. Sec. is used as low pressure fluid transmission pipe, for example water and gas transmission.
Third is pipeline transmission of oil and gas industry.
Last is the size range is also different. I will introduce the shape and specifications of the black hot rolled steel pipe first.
Black steel pipe is divided into round pipe, square pipe and rectangular pipe. The round pipe common specification: outer diameter from one half inch to 8 inch. the wall thickness from 1.2mm to 9.75mm.the length from 4.5m to 12m. Square tube’s size from 20*20mm to 400*400mm,and the rectangular tube’s size from 20*40mm to 300*400mm. Both square tube and rectangular wall thickness are 1.2mm to 20mm. The length from 4.5m to 12m.
The size range of Black annealed steel pipe, for round pipe outside diameter is from 10mm to114mm, Square pipe 10*10-100-100mm, Rectangular pipe:10*20-50*100mm, Wall Thickness: 0.5-1.2mm, Length: 1-6m or as clients requirement.
