JU111，是方形管材的一种称呼，也就是边长相等的的钢管。在抗弯、抗扭强度相同时，重量较轻，所以广泛用于制造机械零件和工程结构。JU111广泛用于建筑，机械制造，钢铁建设等项目，在造船，太阳能发电支架，钢结构工程，电力工程，电厂，农业和化学机械，玻璃幕墙，汽车底盘，机场,锅炉建造，高速路栏杆，房屋建筑，压力容器，石油储罐，桥梁，电站设备，起重运输机械及其他较高载荷的焊接结构件也有大量使用。

Square pipe is a form of address for square pipe, that is, steel pipe with equal side length. When the bending and torsion strength are the same, the weight is lighter, so it is widely used in manufacturing mechanical parts and engineering structures. Square pipes are widely used in construction, machinery manufacturing, steel construction and other projects, such as shipbuilding, solar power bracket, steel structure engineering, power engineering, power plant, agricultural and chemical machinery, glass curtain wall, automobile chassis, airport, boiler construction, high-speed rail, building, pressure vessel, oil storage tank, bridge, power plant equipment, lifting and transportation machinery and other high-load projects. Welded structural parts are also widely used. 

JU111规格尺寸

Square Pipe Specification and Dimension

JU111的规格标示方法：主要是以边宽*边宽*管壁厚度表示。如16×16×0.4～1.5则表示边宽为16mm，管壁厚度为0.4-1.5mm。

Specification marking method of square pipe: mainly expressed by edge width * edge width * wall thickness. If 16 x 16 x 0.4-1.5, the width of the edge is 16 mm and the thickness of the tube wall is 0.4-1.5 mm.

方形钢管规格尺寸

Specification and Dimension of Square Steel Pipe

JU111分类

Square tube classification

按生产工艺分：热轧无缝JU111、冷拔无缝JU111、挤压无缝JU111、焊接JU111。

According to the production process: hot-rolled seamless square pipe, cold-drawn seamless square pipe, extruded seamless square pipe, welded square pipe.

按材质分： 普碳钢JU111、低合金JU111。普碳钢分为：Q195、Q215、Q235、SS400、20#钢、45#钢等；低合金钢分为Q345、16Mn、Q390、ST52-3等。

According to material quality: plain carbon steel square pipe, low alloy square pipe. Common carbon steel is divided into Q195, Q215, Q235, SS400, 20 # steel, 45 # steel, etc. Low alloy steel is divided into Q345, 16Mn, Q390, ST52-3 and so on.

按断面形状分类：(1)简单断面JU111——方形JU111、矩形JU111(2)复杂断面JU111——花形JU111、开口形JU111、波纹形JU111、异型JU111

Classified by section shape: (1) Simple section square pipe - square pipe, rectangular square pipe (2) Complex section square pipe - fancy square pipe, open square pipe, corrugated square pipe, special-shaped square pipe

按表面处理分： 热镀锌JU111、 电镀锌JU111、涂油JU111、酸洗JU111

According to surface treatment: galvanized square pipe, galvanized square pipe, oiled square pipe, pickled square pipe

按用途分类——装饰用JU111、机床设备用JU111、机械工业用JU111、化工用JU111、钢结构用JU111、造船用JU111、汽车用JU111、钢梁柱用JU111、特殊用途JU111

Classification by use - square pipes for decoration, machine tools and equipment, square pipes for machinery industry, square pipes for chemical industry, square pipes for steel structure, square pipes for shipbuilding, square pipes for automobiles, square pipes for steel beams and columns, square pipes for special purposes

按壁厚分类—— 超厚壁JU111、厚壁JU111和薄壁JU111

Classification by Wall Thickness-Ultra-Thick Wall Square Tube, Thick Wall Square Tube and Thin Wall Square Tube

JU111重量计算

Square tube weight calculation

JU111重量计算公式：重量={（长-壁厚）×2÷1000+（宽-壁厚）×2÷1000}×7.85×壁厚×长度。常用规格理论重量见下表。

The formulas for calculating square tube weight are as follows: weight={(length-wall thickness)*2_1000+(width-wall thickness)*2_1000}*7.85_wall thickness*length. The theoretical weight of commonly used specifications is shown in the table below.

备注：以上单位为kg/m，其中壁厚和边长的单位为毫米，即mm。

Note: The above units are kg/m, and the units of wall thickness and side length are mm, that is mm.