Seamless steel pipe is made of whole metal and has no joint on the surface. According to the production method, seamless pipe is divided into hot rolled pipe, cold rolled pipe, cold drawn pipe, extruded pipe, pipe jacking, etc.

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Hot rolled seamless steel pipe is made by automatic continuous rolling machine. In the rolling process, when the temperature reaches the recrystallization temperature, the microstructure and mechanical structure of the steel are changed by controlling different stages such as the initial rolling stage, the finishing rolling stage and the crimping stage, so that it can be deformed into different sizes of pipes.The original casting structure of hot rolled steel pipe (hot rolled seamless pipe) steel plate was destroyed by hot rolling process. The grain of steel material can be refined and the defects of steel plate structure are eliminated. Therefore, hot rolled seamless steel pipe has good mechanical properties and excellent strength. It is widely used to transport fluids, such as oil, natural gas, gas, water and some solid materials, shipbuilding, fertilizer equipment and so on.

Cold-drawn seamless steel pipe produced by drawing, extrusion, perforation and other methods of the whole steel pipe surface without joint steel pipe. It is a circular, square, rectangular steel with hollow section and no joints around it. It is made of steel ingot or solid tube billet through perforation and then made by cold dial.Cold-drawn seamless steel tube can do high precision small batch production. Can be used for mechanical structure, hydraulic equipment of high dimensional precision and good surface finish precision cold drawn seamless pipe.

Seamless steel pipe is mainly used for petroleum geological drilling pipe, cracking pipe for petrochemical industry, boiler pipe, bearing pipe and high-precision structural steel pipe for automobile, tractor and aviation.

General Standard and Application of Seamless Steel Pipe
1ASTM A53 Seamless Black and Hot-dipped Galvanized Steel Pipe
2ASTM A106 Seamless Carbon Steel Pipe for High-Temperature Service
3ASTM A179 Seamless Cold-Drawn Low-Carbon Steel Heat-Exchanger and Condenser Tubes
4ASTM A192 Seamless Carbon Steel Boiler Tubes for High-Pressure Service 
5ASTM A209Seamless Carbon-Molybdenum Alloy-Steel Boiler and Superheater Tubes
6ASTM A210 Seamless Medium-Carbon Steel Boiler and Superheater Tubes
7ASTM A333Seamless Steel Pipe for Low Temperature Service
8ASTM A334Seamless Carbon and Alloy Steel Tubes for Low Temperature Service
9ASTM A335 Seamless Ferritic Alloy-Steel Pipe for High Temperature Service 
10ASTM A500Cold Formed Seamless Carbon Steel Structural Tubing in Rounds and Shapes
11ASTM A519Seamless Carbon and Alloy Steel Mechanical Tubing
12ASTM A523Plain end Seamless Steel Pipe for High Pressure Pipe Type Cable Circuits
13ASTM A618Hot-Formed Seamless High-Strength Low-Alloy Structural Tubing
14ASTM A714High Strength Low Alloy Seamless Steel Pipe
15ASTM A795Black and Hot-Dipped Zinc Coated(Galvanized) Seamless Steel Pipe for Fire Protection USE
16EN 10208-1Steel Pipes for Pipelines for Combustible Fluids-Pipes of Requirement Class A
17EN 10208-2Steel Pipes for Pipelines for Combustible Fluids-Pipes of Requirement Class B
18EN 10216-1 Seamless Steel Tubes for Pressure Purposes-Non-alloy Steel Tubes with Specified Room Temperature Properties
19EN 10216-2 Seamless Steel Tubes for Pressure Purposes-Seamless Non-alloy and alloy steel tubes with specified elevated temperature properties 
20EN 10216-3Seamless Steel Tubes for Pressure Purposes-Alloy fine grain steel tubes
21EN 10216-4 Seamless Steel Tubes for Pressure Purposes-Seamless Non-alloy and alloy steel tubes with specified low temperature properties 
22EN 10224Non-alloy Steel Tubes for the Conveyance of Water and Other Aqueous Liquids
23EN 10255Non-alloy Steel Tubes Suitable for Welding and Threading
24EN 10288Steel Tubes and Fittings for Onshore and Offshore Pipelines
25EN 10297-1Seamless Circular Steel Tubes for Mechanical and General Engineering Purposes-Non-alloy and alloy steel tubes
26EN 10305-1 Steel Tubes for Precision Applications-Seamless Cold Drawn Tubes for Precision Applications
27EN 10305-4 Steel Tubes for Precision Applications-Seamless Cold Drawn Tubes for Hydraulic and Pneumatic Power Systems 
28DIN 30670Polyethylene Coating on Steel Pipes and Fittings
29API 5LSpecification for Line Pipe
30ISO 3183Steel Pipe for Pipelines Transportation Systems