16Mn – JIS:STS49/STPT49 Carbon Low-alloy Bearing Steel Pipe Krobo Steel

Item 6Mn steel tube,16Mn Steel pipe
Standard ASTM,GB,JIS,MTC,etc
Outside  diameter 6-2000mm
 Thickness 1-150mm
Length 5.8m, 6m, or  as  required.
Surface Black painted, PE coated, Galvanized, Varnished, HDPE, etc

16Mn low-alloy steel pipe is: 16Mn is called low-alloy high-strength structural steel Low-alloy high-strength structural steel: the carbon content is 0.1%-0.25%, and the main alloying elements manganese, silicon, vanadium, niobium and titanium are added; its total alloy content is <3%. According to the strength, it is divided into 4 levels of 300, 350, 400 and 450MPa. There are mainly Q295, Q345, Q390, Q420, Q460. : “Q” is the uppercase prefix of the Chinese pinyin of the word “Qu” for yield, and the subsequent number is the minimum yield point (σs) value of the brand, and the subsequent symbols are divided into A, B, C, D, etc. according to the content of impurity elements (sulfur, phosphorus) in the steel from high to low and with the change of carbon and manganese elements. Among them, A and B grade steel are usually called 16Mn.


Usually, the microstructure of the alloy steel pipe determines the structural properties of the steel pipe, however, the strengthening of the structure determines the microstructure. After the cold-rolled alloy steel pipe is rolled, as the cooling environment changes, various structures such as bainite and martensite in the structure also change, which also leads to a great change in the structural performance of the steel pipe. More steel pipes with different strength levels can be obtained by this method to meet different performance requirements. 1. The parent phase is required for structural strengthening, that is, the parent phase for structural strengthening must be contained in the elements of the steel pipe.

  1. Tissue strengthening is a process, including tissue deformation and tissue diffusion. With the change of cooling environment, the structure of alloy steel pipe may change in two ways, that is, with diffusion and without diffusion. In a low temperature environment, non-diffusion determines the process of tissue deformation; in a high temperature environment, diffusion determines the change of tissue structure.
  2. There are two important factors in tissue strengthening, namely tissue strain and environmental cooling. For example, in a heating environment or a cooling environment, the structure of the alloy steel pipe will gradually change as the temperature changes, and the energy state will change from low to high.

In addition, looking at the steel pipe spot, we can know that in the alloy steel pipe, a small amount of medium contains extremely fine density. Therefore, when adjusting the structural properties of steel pipes, we must always pay attention to the microstructure and properties of alloy steel pipes.

Chemical Composition


C% max

Si% max

Mn% max

P% max

S% max








Mechanical Property


Minimum yield strength ReH a
 MPab Nominal thickness mm

Tensile strength Rm
MPab Nominal thickness mm

Elongation in ,
 min, %C


















The special steel grade used for bridges is “16Mnq”, the special steel grade for automobile girders is “16MnL”, and the special steel grade for pressure vessels is “16MnR”.

Chemical Composition
 C% maxSi% maxMn% maxP% maxS% max
Mechanical Property
16MnMinimum yield strength ReH a
 MPab Nominal thickness mm
Tensile strength Rm
MPab Nominal thickness mm
Elongation in ,
 min, %C

Classification By Size:

The length is generally 6000mm, 1250mm,2200mm,12000mm, and the thickness is distinguished by cold rolling and hot rolling. Cold rolling mainly has thickness 1.0mm, 1.2mm, 1.5mm, 2.0mm, 2.5mm, 3.0mm. The main thickness of hot rolling is 3.0mm, 4.0mm, 6.0mm, 8.0mm, 10.0mm, and the width is generally 1000mm, 1219mm, 1500mm.Please contact customer service for general specifications.


Hot-rolled carbon steel pipe are produced by continuous hot-rolled carbon steel technology with hot-rolled steel strip or cold-rolled steel strip as the substrate. The hot-rolled carbon steel sheet is supplied as a rectangular flat plate by cross-cutting; the hot-rolled carbon steel sheet is supplied in coil form by coiling, and the hot-rolled carbon steel sheet coil can be divided into hot-rolled carbon steel sheet coil and cold-rolled carbon steel sheet Coils, they are mainly used in construction, home appliances, automobiles, containers, transportation and household business and other fields. Especially steel structure construction, automobile manufacturing, steel silo manufacturing and other industries.


Their main features are: strong corrosion resistance, good appearance quality, benefit from deep processing, economical and practical, etc.

Application range:

  • After annealing, it is processed into ordinary cold rolling;

(2) The galvanizing unit with pre-annealing treatment device processes galvanizing;

(3) Panels that basically do not need to be processed.

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