Dimensional Technical Requirements of Rectangular Tube

Rectangular pipe is a name for square tube and rectangular tube, that is, steel pipes with equal and unequal side lengths. It is made of rolled steel after processing. Generally, the strip steel is unpacked, flattened, crimped, and welded to form a round pipe. The round pipe is rolled into a square pipe and then cut to the required length.

1. The allowable deviation of the wall thickness of the rectangular tube, when the wall thickness is not more than 10mm, it must not exceed the plus or minus 10% of the nominal wall thickness, and when the wall thickness is greater than 10mm, it is plus or minus 8% of the wall thickness, and the corner and weld area Except for wall thickness.
2. The usual delivery length of rectangular tube is 4000mm-12000mm, mostly 6000mm and 12000mm. The rectangular tube allows the delivery of short-length and non-fixed-length products with a size of not less than 2000mm. It can also be delivered in the form of an interface tube, but the buyer should cut off the interface tube when using it. The weight of short and non-scale products does not exceed the total delivery
5%, for rectangular pipes with a theoretical weight greater than 20kg / m, it should not exceed 10% of the total delivery.
3. The bending of the rectangular tube shall not be greater than 2mm per meter, and the total bending shall not be greater than 0.2% of the total length.

Classification by surface treatment:
Square pipes are divided according to surface treatment: hot-dip galvanized square pipes, galvanized square pipes, oil-coated square pipes, and pickled square pipes.

Classified by use:
Square pipes are classified by purpose: square pipes for decoration, square pipes for machine tools, square pipes for machinery industry, square pipes for chemical industry, square pipes for steel structures, square pipes for shipbuilding, square pipes for automobiles, square pipes for steel beams and columns , Special purpose square tube.

Classified by wall thickness:
Rectangular tubes are classified according to wall thickness: ultra-thick rectangular tubes, thick-wall rectangular tubes, and thin-wall rectangular tubes.

Hardness test:
Hardness is a pointer to measure the hardness of metal materials. The most commonly used method for measuring the hardness of rectangular tubes in production is the indentation hardness method. It uses a certain geometric indenter to press the metal under test under a certain load The surface of the material is tested for hardness based on the degree of indentation.