16Mn Steel is a carbon-manganese steel, carbon content of 0.16%, the yield point is equal to 343MPa (strength level belonging to 343MPa). Less the 16Mn steel alloy content, good weldability, and generally do not have to warm-up before welding.Its total alloy content is less than 3%. According to the strength, it is divided into 4 levels of 300, 350, 400 and 450MPa. There are mainly Q235, Q345, Q390, Q420, Q460 : “Q” is the initial Chinese pinyin of the word “qu” for yielding, the following number is the minimum yield point (σs) value of the grade, and the following symbol is based on the increase in the content of impurity elements (sulfur, phosphorus) of the steel It is divided into four grades A, B, C, D when it is low and with the change of carbon and manganese elements. Among them, A and B grade steels are usually called 16Mn.

16Mn steel belongs to carbon-manganese steel, the carbon content is about 0.16%, and the yield point is equal to 343MPa (strength grade belongs to 343MPa grade). 16Mn steel has less alloy content and good weldability. Generally, it is not necessary to preheat before welding . However, because the hardening tendency of 16Mn steel is slightly greater than that of low-carbon steel, preheating measures must be taken to prevent cold cracks when welding at low temperatures (such as outdoor operations in winter) or on large rigid and large thickness structures.

Brief introduction 16Mn of high-strength low-strength steel

Many buyers of steel materials buy steel plates in China, especially high-strength low-alloy steel. 16Mn is a type of C-Mn steel, its carbon content is 0.1% to 0.25% and with some alloying elements such as manganese (Mn), silicon (Si), vanadium (V), niobium (Nb), titanium (Ti) and other elements. 16 Mn is a type of low-alloy steel with great performance and the most extensive application. This type of steel can be used as an alternative material for many types of steel. Today we present 16Mn as your reference to buy steel plates in China.

As an old Chinese standard, 16Mn is edited from GB 1591-1988 “low alloy structural steel”, it has now been replaced by Q345. Low alloy steel Q345 steel has 5 grades of quality, which are represented by Q345A to Q345E. Q345 steel can be said to be the replacement of the old brand steel of 12MnV, 14MnNb, 18Nb, 16MnRE, 16Mn and other types of steel, instead of only 16Mn of steel. Their corresponding foreign materials are shown below:







Grade 50

SPFC 590

E335 (St 52-3)



Grade 50

SPFC 590




Grade 50

SPFC 590




Grade 50

SPFC 590




Grade 50

SPFC 590



What Is The Difference Between 16Mn And Q345?

The chemical element of Q345 steel is basically the same as that of 16Mn steel. The difference lies in the addition of micro alloying elements, Ti, Nb and V, which can refine the grain, improve toughness, and ultimately improve the mechanical properties of steel. In other words, the integral mechanical properties of Q345 steel are better than those of 16Mn steel, especially its low-temperature performance and allowable stress.

Comparison of standards

16MnGB 28883-2012 Composite Seamless Steel Pipe for Pressure ApplicationNB/T 47008-2010 Carbon steel and alloy steel forgings for pressure equipmentGB 6479-2000 Seamless Steel Pipe for High Pressure Fertilizer EquipmentGB 1591-1988 Low alloy structural steel.
Q345GB/T 1591-2008 Low alloy and high strength structural steel

Comparison of chemical composition

SteeldoYesMinnesotaPAGSCr NorCuNote wellVTheenorthMonth

16Mn is a typical grade of low-alloy high-strength steel, which mainly includes 16Mn steel plate, 16Mn seamless pipe and 16Mn forgings, are widely used in the manufacture of medium and low pressure vessels and oil tanks, as well as general mechanical structural parts.

16Mn material