无缝方管是由无缝钢管冷拔挤压成型的方型钢管，并非直出的焊接方管，而焊接方管也称焊管，是用钢板或带钢经过卷曲成型后焊接制成的方管。焊接方管生产工艺简单，生产效率高，品种规格多，设备资少， 常用材质为：Q235A，Q235C。

Seamless square pipe is a square pipe formed by cold-drawing and extrusion of seamless steel pipe, not a straight welded square pipe. Welded square pipe, also known as welded pipe, is a square pipe made of steel plate or strip steel after curling and forming. Welded square pipe has the advantages of simple production process, high production efficiency, many varieties and specifications, and less equipment. Commonly used materials are Q235A and Q235C. 

一、焊接方管是一种空心方形截面型钢方管,也称为空心冷弯型钢.它是以热轧或冷轧带钢或卷板为坯料经冷弯曲加工成型后再经高频焊接制成的方形截面形状尺寸的型钢。

1. Welded square pipe is a hollow square section steel square pipe, also known as hollow cold-formed steel. It is a square section shape and size steel made by hot-rolled or cold-rolled strip or coil plate after cold bending processing and high frequency welding. 

厚壁方管除壁厚增厚外情况,其角部尺寸和边部平直度均达到甚至超过电阻焊冷成型方管的水平，R角的大小一般是壁厚的2倍-3倍之间.也可以根据客户的需要，生产客户所需大小的R角方管；

In addition to wall thickness, the corner size and flatness of thick-walled square tubes reach or even exceed the level of resistance welding cold-formed square tubes. The size of R angle is generally between two and three times of wall thickness. The R angle can also be manufactured according to the needs of customers. 

二、无缝方管是一种具有中空截面、周边没有接缝的长条钢材.是用无缝管通过模具的4面挤压形成的方管，方管具有中空截面,大量用作输送流体的管道.主要应用于液体输送,液压支架,机械结构,中低压.高压锅炉管,热交换管,气体.石油等行业.他比焊接的更坚固，不会出现裂缝。

2. Seamless square pipe is a kind of long steel with hollow section and no seams around it. It is a square pipe formed by extrusion of seamless pipe through four sides of the die. The square pipe has hollow section and is widely used as a pipeline for conveying fluid. It is mainly used in liquid conveying, hydraulic support, mechanical structure, medium and low pressure, high pressure boiler pipe, heat exchange pipe, gas, oil and other industries. It is stronger than welding and will not. Cracks appeared.