The cutting of large-diameter steel pipe is usually done by mechanized cutting methods, because manual cutting is less efficient for large-diameter steel pipe and the cut is not smooth. Mechanized cutting methods include cutting machine, flame cutting and laser cutting.

Cutting machine: Cutting machine is a mechanized cutting tool using a cutting wheel, suitable for small diameter steel pipe and metal pipe. Specific steps include determining the cutting position and length, fixing the steel pipe on the cutting machine, turning on the cutting machine, using the automatic or manual cutting function, turning off the machine after cutting, and applying sandpaper to smooth the edges.1

Flame cutting: flame cutting is a commonly used mechanized cutting method, suitable for large diameter steel pipe cutting. Specific steps include determining the cutting position and length, connecting high-pressure oxygen and gas, igniting the fire to make the flame jet, adjusting the cutting caliber and cutting speed, jetting the flame to the cutting position, when the flame cuts to the inside of the steel pipe, cutting along the necessary lines until the desired length is reached, and after the cutting is finished, the edges should be struck with pliers and hammer.

Laser cutting: Laser cutting is a high-precision mechanized cutting tool for steel pipes and metal tubes of various calibers. Specific steps include determining the cutting position and length, setting the parameters of the laser cutting machine, such as power, frequency, speed, etc., respectively, fixing the two ends of the steel pipe in the laser cutting machine through the clamps, starting the laser cutting machine, waiting for the end of the cutting, and after the end of the cutting, using sandpaper to polish the edges.

For the cutting of large-diameter steel pipes, manual cutting methods exist, but they are less efficient and the cut is not smooth, so they are usually not used. Instead, mechanized cutting methods, such as cutting machines, flame cutting, and laser cutting, can provide higher cutting efficiency and smoother cuts.