Seamless square pipe is a square steel pipe with four corners. It is a square steel pipe formed by cold drawing and kneading of seamless steel pipe.

The main properties of square tubes include: plasticity, hardness and fatigue. Plasticity refers to the ability of a metal material to undergo plastic deformation (permanent deformation) without damage under the effect of load.

Hardness is a measure of how soft and hard a metal material is. At present, the most commonly used method for measuring hardness in production is the indentation hardness method, which uses an indenter of a certain geometric shape to press into the surface of the metal material to be tested under a certain load, and determines its hardness value according to the degree of indentation.

Strength, plasticity, and hardness are all indicators of mechanical properties of metals under static load. In fact, many machine parts are operated under cyclic loading, under which conditions part fatigue occurs. Therefore, the higher the fatigue resistance of the seamless square tube, the better the performance of the steel tube.

Classification of seamless square tubes:

1. According to the process - arc welded pipe, electric resistance welded pipe (high frequency, low frequency), gas welded pipe, furnace welded pipe

2. According to the welding seam - straight seam welded pipe, spiral welded pipe

3. Classified by section shape

4. Classification by wall thickness - thin-walled steel pipe, thick-walled steel pipe

5. Classification by use - steel pipes for thermal equipment, steel pipes for machinery industry, steel pipes for petroleum, geological drilling, steel pipes for containers, steel pipes for chemical industry, steel pipes for special purposes, and others.

The formula for calculating the weight of the square tube theory is:

4*Wall thickness*(side length-wall thickness)*7.85, where the side length and wall thickness are both in millimeters, directly put the value into the formula, and calculate the weight of the square tube per meter, in grams.

For example: 30*30*2.5mm square tube, according to the formula, the weight per meter is:

4*2.5*(30-2.5)*7.85=2158.75 grams, about 2.16 kilograms.