What is Seamless Steel Pipe

How to define a seamless steel pipe? Seamless steel pipe is also known as smls pipe, it is manufactured without seam welds. These pipes are manufactured from steel billets which are heated and drilled to generate the tubular section.
Seamless Pipe in Oil and Gas Industry(OCTG Pipe)
Seamless pipes can be utilized for different purposes in the oil and gas industry such as upstream operations, midstream operations like carrying and distribution of different fluids like oil, gas, slurries, steam, and acids. Also used in downstream operations like process piping to refine oil and gas in secondary produce. Seamless Pipes are suitable to be used in general plumbing applications in this industry.
Various Types of Seamless Steel Pipes Manufactured by AGICO
AGICO owns hot-rolled seamless steel pipe production line is the third most advanced small-diameter continuous rolling mill in China. It can produce OCTG Pipes, Fluid Pipes, Boiler Pipe and Tubes, High value-added products such as Hydraulic Pillar Pipes, Cylinder Sleeves, Structural Pipe, Seamless Pipes for Shipbuilding and Bearings.
ASTM/ASME Standard – Seamless Steel Pipe
Product name | Executive standard | Steel code/ Steel grade |
---|---|---|
Black and Hot-dipped Zinc-coated Steel Seamless Pipes | ASTM A53 | GR.A, GR.B, GR.C |
Seamless Carbon Steel for High Temperature Service | ASTM A106 | GR.B, GR.C |
Seamless Cold-drawn Low-Carbon Steel Heat-Exchanger and Condenser Tubes | ASTM A179 | Low Carbon Steel |
Seamless Carbon Steel Boiler Tubes for High Pressure | ASTM A192 | Low Carbon Steel |
Seamless Cold-drawn Intermediate Alloy Steel Heat-exchanger and Condenser Tubes | ASTM A199 | T5, T22 |
Seamless Medium-carbon Steel Boiler and Superheater Tubes | ASTM A210 | A1, C |
Seamless Ferritic and Austenitic Alloy Steel Boiler, Superheater and Heat-exchanger Tubes | ASTM A213 | T5, T5b, T9 , T11, T22 ,T91 |
Seamless Carbon and Alloy Steel for Mechanical Tubing | ASTM A333 | Grade1 Gr. 3,Gr..6, Gr.8 , Gr. 9 |
Seamless Cold-drawn Carbon Steel Feedwater Heater Tubes | ASTM A556 | A2, B2 |
Round and shaped steel cold formed welded and seamless carbon steel structural pipe. | ASTM A500 | Grade A, B, C, D |
Welded and seamless steel pipe for piling purposes. | ASTM A252 | A252 Grade 1, 2 & 3 |
For seamless ferritic alloy-steel pipe for high-temperature service | ASTM A335 | A/SA 335 P1, P2, P11, P12, P15, P22, P91, P92, P122 |
Din Standard – Seamless Steel Pipe
Product name | Executive standard | Steel code/ Steel grade |
---|---|---|
Seamless Steel Tubes for Elevated Temperature | DIN 17175 | St35.8,St45.8, 10CrMo910, 15Mo3, 13CrMo44, STPL340, STB410, STB510, WB36 |
Seamless Circular Tubes of Non Alloys Steels with Special Quality Requirements. | DIN 1629 | St37.0, St44.0, St52.0 |
Seamless steel tubes for pressure purposes | EN 10216 | P235GH TC1, P235GH TC2, 16Mo3 |
hydraulic and pneumatic power system, low-voltage circuit, power steering, fuel circuit, vibration reduction, and such. | EN 10305 | St33.2 |
specifies the Seamless steel tubes used forMechanical and Automobile. | DIN 2391 | St35, St45, St52 |
Seamless Steel Tubes | DIN 2440 | St33.2 |
JIS Standard – Seamless Steel Pipe
Product name | Executive standard | Steel code/ Steel grade |
---|---|---|
High pressure and high temperature service | JIS G3454/5/6 | JIS G3454(STPG370, STPG410), JIS G3455(STS370, STS410, STS480), JIS G3456(STPT370, STPT410, STPT480) |
Tubes used for machinery, automobiles, bicycles, furniture, appliances and other machine parts. | JIS G3445 | STKM11A, STKM12(A,B,C), STKM13(A,B,C), STKM14(A,B,C). |
Carbon steel/Alloy steel boiler and heat exchanger tubes | JIS G3461,2 | G3461(STB340, STB410, STB510) G3462(STBA22, STBA23) |
Seamless steel tubes for high pressure gas cylinder | JIS G3429 | STH11, STH12, STH21, STH22 |
Heat resistant alloy steel pipes that are used for high temperature conveying fluid pipes for heaters and boiler tubes. | JIS G3458 | STPA 12, STPA 20, STPA 22, STPA 23, STPA 24, STPA 25, STPA 26 |
Seamless Pipe Dimensions
(WT)mm | 0.6-0.8 | 0.9-1.2 | 1.3-1.6 | 1.7-2.2 | 2.3-2.9 | 3-4.5 | 4.6-5.5 | 5.6-7.5 | 7.6-9 | 9.1-12 | 12.1-16 | 16.1-24 | 24.1-32 |
(OD)mm | |||||||||||||
5–7 | ● | ● | ● | ● | ● | ||||||||
8–10 | ● | ● | ● | ● | ● | ● | |||||||
11–16 | ● | ● | ● | ● | ● | ● | |||||||
17-25 | ● | ● | ● | ● | ● | ● | ● | ||||||
26-35 | ● | ● | ● | ● | ● | ● | |||||||
36-45 | ● | ● | ● | ● | ● | ||||||||
46-56 | ● | ● | ● | ● | ● | ● | ● | ||||||
57-65 | ● | ● | ● | ● | ● | ● | |||||||
66-76 | ● | ● | ● | ● | ● | ● | |||||||
77-100 | ● | ● | ● | ● | ● | ● | |||||||
101-114 | ● | ● | ● | ● | ● | ||||||||
115-133 | ● | ● | ● | ● | ● | ● | ● | ● | |||||
134-159 | ● | ● | ● | ● | ● | ● | ● | ● | |||||
160-219 | ● | ● | ● | ● | ● | ● | ● | ● | |||||
220-273 | ● | ● | ● | ● | ● | ● | ● | ||||||
274-325 | ● | ● | ● | ● | ● | ● |
AGICO may produce GB standard of steel pipe to meet domestic Asian buyers’ demand, we also provide wide range of international industrial standard such as ASTM, ANSI and API, ASME, DIN, JIS .
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Why Seamless Steel Pipe is Used Widely

Seamless Steel Pipe can be produced in the following process, hot rolling or cold drawn, it has the advantages of easy bending and flanging, and can bear certain degrees of pressure, which makes it suitable for boiler and pressure vessel for high-pressure application.
Structural and Tested Pipe is produced by AGICO in seamless type with a variety of sizes to meet the structural and mechanical piping requirements for applications in water, petroleum, oil & gas, construction and other industries. We supply large quantity of carbon steel pipe and low alloy high strength steel pipe for worldwide customers.
Seamless steel pipe can be processed in the following methods: cut to length, threaded or grooved. And the coating method includes black/red lacquer, varnish painting, hot dip galvanization, etc.
Seamless steel Pipe vs Seamless Steel Tube
In the market there are seamless steel tube and seamless steel pipe, there is only a slight difference, both seamless steel tube and seamless steel pipe are often used for the same type of steel product, for they have same type of round hollow shape, there are important distinctions between the two when defining seamless pipe and seamless tube. Seamless Tubes are measured by the outside diameter (OD) and wall thickness. While seamless pipe is measure by its inside diameter (ID). According to their application, seamless tube is generally used in structural and aesthetic applications whereas seamless pipe is used for transporting fluids, liquids, and gases.
AGICO supplies various types of seamless steel pipe and tube product for different industries, if you need more details about seamless pipe product, feel free to contact us now!