Square tube is a commonly used steel material with unique structure and characteristics, therefore it has different usage methods in different occasions.

1. 方管在建筑领域的使用：在建筑领域，方管通常被用于搭建钢结构、支撑和框架等方面。例如，在大型建筑物中，方管常被用作柱子、梁和横梁的支撑结构，以提供稳定的承重能力。此外，方管也可以用于搭建脚手架、建筑门窗框架等应用。

1. Use of square pipes in the construction field: In the construction field, square pipes are usually used to build steel structures, supports, and frames. For example, in large buildings, square tubes are often used as supporting structures for columns, beams, and beams to provide stable load-bearing capacity. In addition, square tubes can also be used for applications such as scaffolding and building door and window frames.

2. 方管在工业领域的使用：在工业领域，方管常用于制造机械设备、输送系统等。例如，方管可以用来制作输送带支撑架、输送管道等，用于物料传输和输送。此外，方管还广泛用于制造各种类型的机械设备，如机械手臂、输送机、装卸设备等。

2. Use of square tubes in the industrial field: In the industrial field, square tubes are commonly used for manufacturing mechanical equipment, conveying systems, etc. For example, square tubes can be used to make conveyor belt support frames, conveyor pipelines, etc., for material transmission and conveying. In addition, square tubes are widely used in the manufacturing of various types of mechanical equipment, such as robotic arms, conveyors, loading and unloading equipment, etc.

3. 方管在农业领域的使用：在农业领域，方管通常被用于搭建温室大棚、畜牧养殖设施等。方管可以用于制作温室大棚的骨架结构，提供稳定的支撑，并方便安装和拆卸。此外，方管还可以用于制作畜牧养殖设施的围栏、圈舍等。

3. Use of square tubes in agriculture: In agriculture, square tubes are usually used to build greenhouses, animal husbandry facilities, etc. Square tubes can be used to make the framework structure of greenhouse greenhouses, providing stable support and facilitating installation and disassembly. In addition, square tubes can also be used to make fences, pens, etc. for livestock breeding facilities.

4. 方管在家具和装饰领域的使用：方管还可以用于制作家具和装饰品，如桌椅、衣架、货架、展示架等。方管具有较高的强度和稳定性，可以为家具提供坚固的支撑结构，并具有一定的设计美感。

4. Use of square tubes in the field of furniture and decoration: Square tubes can also be used to make furniture and decorations, such as tables and chairs, hangers, shelves, display racks, etc. Square tubes have high strength and stability, which can provide a sturdy support structure for furniture and have a certain design aesthetic.

总的来说，方管由于其结构稳定、强度高、易加工和广泛的适用性，在建筑、工业、农业以及家具和装饰等领域都有着重要的应用。不同类型的方管在不同场合根据需求的不同，可以选择不同的材质、尺寸和厚度，以满足特定的使用要求。

Overall, square tubes have important applications in fields such as architecture, industry, agriculture, furniture, and decoration due to their stable structure, high strength, ease of processing, and wide applicability. Different types of square tubes can be selected from different materials, sizes, and thicknesses according to different needs in different situations to meet specific usage requirements.