The two types of steel pipes you are talking about are two categories.
Galvanizing means that the surface of the steel pipe is galvanized, which may be a welded pipe or a seamless pipe;
Seamless refers to the manufacturing process of steel pipes, which are welded and seamless.
The seamless steel pipe is made of steel ingot or solid tube blank by perforation, and then made by hot rolling, cold rolling or cold drawing. It has a hollow section and is used as a pipe for conveying fluid. The steel pipe is compared with solid steel such as round steel. It is a kind of economical section steel when it has the same bending and torsional strength. It is widely used in the manufacture of structural parts and mechanical parts, such as oil drill pipes, automobile drive shafts, bicycle frames and steel scaffolds used in construction. .
The galvanized steel pipe is divided into two types: hot-dip galvanizing and electro-galvanizing. The hot-dip galvanizing layer is thick, with uniform plating, strong adhesion and long service life. The cost of electroplating is low, the surface is not very smooth, and its corrosion resistance is much worse than that of hot-dip galvanized pipes.