Ган хоолой ба гагнасан ган хоолойн хооронд ямар ялгаа …
1. Different formation methods 1) Seamless steel pipe: a steel pipe made of a single piece of metal with no seams on the surface. 2)Welded steel pipes: steel strips or steel plates that are bent and deformed into round or square shapes and then welded into steel pipes with seams on the surface. &...
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