What are square and rectangular tubes

Square steel pipe is a kind of hollow square cross section light thin wall steel tube, also known as steel refrigeration bend section. It is made of Q235 hot rolled or cold rolled strip steel or coil plate as base material by cold bending forming and then by high frequency welding made of square section shape and size of steel. In addition to the thickening of the wall, the corner size and edge flatness of hot rolled extra-thick wall Square steel pipe reach or even exceed the level of resistance welding cold forming Square steel pipe. Good comprehensive mechanical properties, weldability, cold, hot working and corrosion resistance, with good low temperature toughness.rectangular square tubing is a hollow strip of steel, also known as flat tube, flat Square steel pipe or square flat tube (as the name implies). At the same time of bending and torsional strength, the weight is relatively light, so it is widely used in manufacturing mechanical parts and engineering structures.

The purpose of the Square steel pipe construction, machinery manufacturing, steel construction projects, shipbuilding, solar power stents, steel structure engineering, power engineering, power plants, agricultural and chemical machinery, glass curtain wall, automobile chassis, airport, the boiler construction, highway railings, housing construction, pressure vessel, oil tank, bridge, power station equipment, Lifting and transportation machinery and other high load welding structures.

There are two main production methods of rectangular square tubings, namely, cold rolling and hot rolling. Hot rolling of rectangular square tubing is made of hot rolled strip steel after processing and rolling. Cold drawn or cold rolled precision moment tube, cold rolled moment tube is used for mechanical structure, hydraulic equipment with high dimensional accuracy and good surface finish cold drawn or cold rolled precision moment tube.

Cold-drawn rectangular square tubing, as the starting raw material is a hot rolled strip coil, in use, first with an acid, the oxide skin absorption, and then cold rolling, so that the production of the cold rolled steel tube, hardness and strength, but the toughness will be slightly reduced. Therefore, this will lead to a reduction in performance at the time of stamping, and cold rolled rectangular square tubing production can only be simply deformed parts manufacturers. Cold rolling, after continuous annealing process. Square steel pipe, cold rolled production quality, as well as surface appearance, as well as the accuracy of the size of hot rolled rectangular square tubing is better than the above, the thickness is much thinner, so has been favored by many manufacturers. Many industries, on the other hand, are very widely used.

The difference between square and rectangular square tubings

1.the cross section is different: the cross section of the Square steel pipe is square; The cross section of a rectangular square tubing.
2. Different uses:
Square steel pipe USES: construction, machinery manufacturing, steel construction projects, shipbuilding, solar power stents, steel structure engineering, power engineering, power plants, agricultural and chemical machinery, glass curtain wall, automobile chassis, airport, boiler building, highway railings, housing construction, pressure vessel, oil storage tanks, Bridges, power station equipment.
torque tube uses: a large number of used for conveying fluid pipeline, such as petroleum, natural gas, water, gas, steam, etc., in addition, in the bending and torsional strength at the same time, light weight, so it is also widely used in manufacturing machinery parts and engineering structures. Also commonly used for the production of conventional weapons, gun barrels, shells and so on.
3.the scope of coverage is different: Square steel pipe is a kind of rectangular square tubing, contained in the rectangular square tubing.

Molding method

1.solid bent
Solid bending, as the name implies, is compacted bending, and the inner and outer rollers and the inner and outer walls of the tube blank are compacted in both directions during solid bending.
1) The advantages of solid bending are small rebound, accurate forming, and as long as the roller type is accurate, the R of inner Angle forming is more accurate.
2) The disadvantage of solid bending is the stretching/thinning effect. First, the real bending will produce tension at the bending, and the stretching effect will shorten the longitudinal length of the bending line; Second, the metal will be thinned by stretching at the bend.
2. empty
Empty bending is through the one-way contact between the outer roller and the outer wall of the tube blank to form a bending moment to bend the material. Empty bending will cause compression of the bending line. The compression effect makes the bending line lengthwise and the metal at the bending place appears to accumulate and thicken, which is the compression/thickening effect of empty bending.
1) The advantage of empty bending is that side length bending can be carried out when real bending is not possible, such as the top/side synchronous bending and finishing of square rectangular square tubing. The empty bend can also bend the inner Angle R

2) The disadvantage of air bending is that in the upper/side synchronous air bending, due to the pressure of the upper roll and the lower roll at the same time, the forming force is easy to exceed the critical point, resulting in the edge instability concave, and will also affect the stable operation of the unit and forming quality. This is the Square steel pipe and circular tube empty bending molding different characteristics.