無縫方管是由無縫鋼管冷拔擠壓成型的方型鋼管，并非直出的焊接方管，而焊接方管也稱焊管，是用鋼板或帶鋼經過卷曲成型后焊接制成的方管。焊接方管生產工藝簡單，生產效率高，品種規格多，設備資少， 常用材質為：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、焊接方管是一種空心方形截面型鋼方管,也稱為空心冷彎型鋼.它是以熱軋或冷軋帶鋼或卷板為坯料經冷彎曲加工成型后再經高頻焊接制成的方形截面形狀尺寸的型鋼。

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況,其角部尺寸和邊部平直度均達到甚至超過電阻焊冷成型方管的水平，R角的大小一般是壁厚的2倍-3倍之間.也可以根據客戶的需要，生產客戶所需大小的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、無縫方管是一種具有中空截面、周邊沒有接縫的長條鋼材.是用無縫管通過模具的4面擠壓形成的方管，方管具有中空截面,大量用作輸送流體的管道.主要應用于液體輸送,液壓支架,機械結構,中低壓.高壓鍋爐管,熱交換管,氣體.石油等行業.他比焊接的更堅固，不會出現裂縫。

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.