Stainless steel is often divided into martensitic steel, ferritic steel, austenitic steel, austenitic ferritic (duplex) stainless steel and precipitation hardening stainless steel, etc. In addition, according to the composition can be divided into: chromium stainless steel, chromium nickel stainless steel and chromium manganese nitrogen stainless steel.

Carbon steel is mainly refers to carbon mass fraction is less than 2.11% without special add steel alloy elements, commonly used material: A36 / S235JR/A283 / A514 / A572 / S355JR/A709 / A285 / A387 / A515 / A516 / A533 / A537 / A588, etc.

API pipeline pipe is a pipeline pipe belonging to the United States petroleum standard, and the pipeline pipe is to extract the oil, steam, and water from the ground through the pipeline pipe to the oil and gas industry enterprises. The pipeline pipe comprises a seamless pipe and a welded steel pipe, the pipe end has a flat end, a threaded end and a socket end; The connection modes are end welding, collar connection, socket connection, etc.