Seamless steel tubes have hollow sections and are widely used as pipelines for conveying fluids, such as pipelines for conveying petroleum, natural gas, gas, water and some solid materials.Steel tubes can be divided into round tubes and special-shaped tubes according to the shape of cross-sectional area.Since a circle has the largest area with the same circumference, more fluid can be transported in a circular tube.In addition, when the annular section bears internal or external radial pressure, the force is more uniform, so most steel tubes are round tubes.
However, the circular pipe also has certain limitations, such as under the condition of plane bending, the circular pipe is not as strong as square, rectangular pipe bending strength, some agricultural machinery framework, steel and wood furniture, etc., are commonly used square, rectangular pipe.Other special-shaped steel tubes with different section shapes are required according to different USES.

Seamless steel pipes of different usage:
1.Seamless steel tubes for construction
Standards: GB/T8162, ASTM A501, JIS G344,ASTM A500
Common grades: 10#, 20#, 35#, 45#, 40Mn2, 45Mn2, 27SiMn, 20Cr, 40Cr, 20CrMo, 35CrMo, 38CrMoA1, 50CrV, 30CrMnSi
2.Seamless steel tubes for conveying fluids
Standard: GB/T8163,ASTM A53, ASTM A192, JIS G3452, DIN 1629
Commonly used steel grades: 10#, 20#, Q295, Q345
3.Line pipes and petroleum seamless steel casing & tubing
Standard: API 5CT,API 5L
Common grades: J55,K55,L80, N80,P110,grade B, X42,X46,X52,X56,X60,X65,X70
4.Seamless steel tubes for gas cylinders
Standard:GB 18248,EN 10297,EN 10083,JIS G3429
Commonly used steel grades:34Mn2V, 30CrMo, 35CrMo,37Mn,34CrMo4,30CrMoSiA,38Mn6,30CrMo4,42CrMo4
5.Seamless steel tubes for high pressure boilers
Standard: GB5310,ASTM A106, ASTM A210C, ATSM A213, JIS G3461, JIS G3462, DIN 17175,BS3059: Part 2
Common steel grades: 20G, 20MnG, 25MnG, 15MoG, 20MoG, 12Cr1MoVG, 15CrMoVG, 12Cr2MoG, 12Cr2MoWVTiB, 12Cr3Movsib
6.Seamless steel tubes for low and medium pressure boilers
Standard: GB3087,ASTM A179, ASTM A192
Common brands: 10#, 20 #
7.High pressure seamless steel tubes for fertilizer equipment
Standard: GB6479,ISO 9329-2
Common steel grades: 10#, 20G, Q345, Q390, 10MoVNb, 12CrMo, 15CrMo, 12Cr2Mo
8.Petroleum cracking seamless steel pipe
Standard: GB/T9948, JIS G3441
Common brands: 10#, 20#, 12CrMo, 15CrMo, 1Cr2Mo, 1Cr5Mo
9.Seamless steel pipe for car half axle sleeve
Standard: Q/OHAD001 YB/T5035,DIN 1629
Common steel grades: 45Mn2, 45#, 25MnCr
10.Hot rolled seamless steel tubes for hydraulic props
Standard: Q/OHAD010 GB/T17398
Common steel grade: 27SiMn
11.Seamless steel pipe for ship
Standard: GB/T5312,DIN 2391
Commonly used brands: Q320, Q360, Q410, Q460 and Q490
12.Cold drawn precision seamless steel tube
Standard: GB/T3639, GB/T8713
Common steel grades: 10#, 20#, 35#, 45#, 30CrMo
13.Seamless steel pipe for geological drilling
Standard: YB/T5052,YB235
Commonly used steel grades: DZ40, DZ50
Seamless steel tube is a kind of economic section steel, has a very important position in the national economy, widely used in petroleum, chemical industry, boiler, power station, ship, machinery manufacturing, automobile, aviation, aerospace, energy, geology, construction and military sectors.IMRI supplies seamless steel pipes of all kinds of usages.Just tell us your requirements and you will get seamless steel pipes which meet your needs from us.