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1215 Carbon Steel: Composition, Properties, and Applications

1215 steel machining


Welcome to HDC, your prime destination for bespoke metal component machining services. HDC specializes in harnessing our extensive capabilities and adeptness in processing 1215 carbon steel to furnish bespoke solutions tailored to your distinctive requisites. Our unwavering dedication to exactitude and excellence distinguishes HDC as the preeminent collaborator, providing an effortlessly efficient encounter in the realm of 1215 carbon steel machining.

Armed with state-of-the-art technologies and an adept workforce, HDC excels in managing a diverse array of projects entailing 1215 carbon steel. Our team’s profound comprehension of the material empowers us to implement cutting-edge machining methodologies, ensuring the delivery of components with meticulous tolerances and elaborate designs. Opt for HDC for a dependable and all-encompassing approach to 1215 carbon steel machining, where your specifications are met with meticulous precision and meticulous attention to detail.

With a validated history of successfully concluding ventures linked to 1215 carbon steel, HDC stands as a venerated entity in the industry. Our client-centric methodology, coupled with an emphasis on superiority, assures not only finely wrought components but also an unhitching experience. Unearth the HDC advantage in 1215 carbon steel machining, and let us be your favored collaborator in actualizing your concepts into reality with consummate excellence and unwavering reliability.1215 carbon steel 1

What is 1215 Carbon Steel?

1215 carbon steel that is also called resulfurized carbon steel is a free-machining steel possessing the higher sulfur percentage than standard carbon steels. The improved sulfur content can offer better machinability through the formation of ferric and manganese sulfides, which will act as chip breakers during machining operations. Such constitutes higher productivity, less wear and tear of the tool, and a smoother surface finish as compared with the other carbon steels. The 1215 steel is one in the most common used materials for parts which requires complex machining, including bolts, screws, bushings and fittings, where the dimensions and the surface finish of the component are critical. On the other hand, its low carbon content gives it soft ductility, weldability, and formability thus making it strive well in many fabrication processes.

How Is 1215 Carbon Steel Named?1215 carbon steel 2

The naming of 1215 carbon steel adheres to the AISI four-digit numbering system, where the first digit “1” identifies it as carbon steel, emphasizing carbon as its primary alloying element. Unlike other steel grades that might use the second digit to indicate secondary alloying elements, 1215’s designation skips this to focus on its carbon content and machinability enhancements. The last two digits “15” denote a carbon content of approximately 0.15% by weight, classifying it as a mild steel with superior machinability and weldability, thanks to the addition of sulfur or phosphorus. This systematic naming reflects its composition, low carbon percentage, and the adjustments made to optimize its machining capabilities, making 1215 ideal for components requiring extensive machining.

How Are Base Carbon Steel Grades Classified?

Base carbon steel grades are classified by their carbon content and additional elements, following the AISI/SAE numbering system. Low carbon steels (up to 0.3% carbon) are known for their ductility and weldability, medium carbon steels (0.3% to 0.6% carbon) offer a balance of strength and ductility, and high carbon steels (0.6% to 1.0% carbon) are valued for their strength and wear resistance. The AISI/SAE system uses a four-digit code, where the first two digits (“10” for plain carbon steels, “11” for those with added sulfur or phosphorus for machinability) and the last two represent the carbon content in hundredths of a percent. This classification facilitates understanding of steel properties and applications, ranging from construction materials to cutting tools.1215 carbon steel 3

What Are the Advantages and Disadvantages of 1215 Carbon Steel?

1215 carbon steel has outstanding machinability in conjunction with competitive price thanks to it’s sulfur added which allows the chip breaking better during machining that result in the surface finish improvement and extended tool life. Its unique characteristic of free-cutting not only makes it a good fit for precise machining but also for machining processes that have to be done in intricate ways. In addition, 1215 steel is quite weak and has low ductility which reduce the potential of using in high stress applications or processing operation that require higher strength. Furthermore, its weldability may also be compromised by sulfur content, therefore when welding may require to specifically take precautions. However, these drawbacks notwithstanding,1215 carbon steel still occupies a significant position in industries where the ease of machinability and affordability is considered.

1215 Carbon Steel Chemical Composition

1215 Carbon steel is a low-alloy, fast cutting steel, widely recognized as the standard screw stock. As a standard resulfurized and rephosphorized carbon steel, it is generally designed for screw machining such as bushings, inserts, knives, hammers, saws couplings, studs, pins, and other tools, due to its benefits of excellent cutting speeds and machining properties, like high toughness, good toughness, wear resistance, and formability.1215 carbon steel 4

Component Wt.%
Carbon (C) 0.0 – 0.09
Manganese (Mn) 0.75 – 1.05
Phosphorus (P) 0.04 – 0.09
Sulfur (S) 0.26 – 0.35
Iron (Fe) Balance

The Influence of Various Elements on the Properties of 1215 Carbon Steel

The properties of 1215 carbon steel are influenced by its carbon, manganese, sulfur, phosphorus, silicon, and trace element content. Carbon affects hardness and machinability, manganese refines grain and enhances mechanical properties, sulfur aids machinability but can reduce ductility, and phosphorus may improve machinability or induce brittleness. Silicon acts as a deoxidizer and enhances strength, while trace elements impact corrosion resistance and mechanical strength, allowing for tailored properties in various applications.

1215 Carbon Steel Mechanical Properties1215 carbon steel 5

Mechanical Properties Metric English
Ultimate Tensile Strength 540 MPa 78300 psi
Tensile Yield Strength 415 MPa 60000 psi
Elongation at Break 10 % 10 %
Reduction of Area 35 % 35 %
1215 Steel Hardness, Brinell 167 167
1215 Steel Hardness, Knoop 188 188
1215 Steel Hardness, Rockwell B 85 85
1215 Steel Hardness, Vickers 175 175
Modulus of Elasticity 200 GPa 29000 ksi
Bulk Modulus 160 GPa 23200 ksi
Shear Modulus 80.0 GPa 11600 ksi
Poissons Ratio 0.29 0.29

1215 Carbon Steel Physical Properties

Physical Properties Metric English Comments
Density 7.87 g/cc 0.284 lb/in²
Electrical Properties
Electrical Resistivity 0.0000174 ohm-cm 0.0000174 ohm-cm Typical steel
Thermal Properties
Specific Heat Capacity  0.472 J/g-°C 0.113 BTU/lb-°F Typical steel
Thermal Conductivity 51.9 W/m-K 360 BTU-in/hr-ft²-°F Typical steel

1215 Carbon Steel Equivalent Materials1215 carbon steel 6







AISI 1213

AISI 12L13

AISI 12L14




SAE 1213

SAE 1215

SAE 12L13

SAE 12L14











DIN 1.0715

DIN 9SMn28

DIN 11SMn30

DIN 1.0718

DIN 9SMnPb28

DIN 11SMnPb30

DIN 1.0736

DIN 9SMn36

DIN 11SMn37












JIS 11SMn28





JIS 11SMnPb28


JIS 12SMn35



















BS 230M07

BS 11SMN30

BS 220M07

BS 11SMnPb30

BS 11SMn37






UNI 9SMn23


Spain UNE

UNE 11SMn28

UNE 11SMnPb28





GB/T U71152

GB/T Y15

GB/T U72152

GB/T Y15Pb

Sweden SS

SS 1912

SS 1914















ISO 11SMn28

ISO 11SMn30

ISO 11SMnPb30

ISO 11SMnPb28

ISO 12SMn35

ISO 11SMn37



UNS G12130

UNS G12150

UNS G12144

UNS G12134







ASTM A29 Grade 1215

ASTM A29 Grade 12L15

ASTM A510 Grade 12L15

ASTM A510 Grade G12150

ASTM A519 Grade 1215

ASTM A576 Grade G12150

ASTM A738 Grade E

ASTM A29 Grade 12L14

ASTM A510 Grade 12L14

ASTM A519 Grade 12L14

ASTM A576 Grade 12L14

How Is 1215 Carbon Steel Processed?

1215 Carbon Steel is predominantly processed by machining since that is its key feature due to the high sulfur content which gives manganese sulfide inclusion which makes it easy to break chips when machining. Such complex parts with accurate cutting are manufactured through turning, drilling, milling and tapping processes. Furthermore, a cold working processing technique such as cold drawing or cold rolling can be used to modify its mechanical properties and to enhance its surface finish, while heat treatment, particularly in stress relieving, can mitigate internal stresses and assure dimensional stability. Different surface finishings, coatings, heat treatments, or plating can be used to adust 1215 steel further, giving it a wider range of corrosion resistance, surface hardness, or appealing visual aspects and making it applicable to many fields.1215 carbon steel 7

What Challenges Are Encountered in Processing 1215 Carbon Steel?

1215 carbon steel’s excellent machinability, however, confers a distinction. The alloy’s high sulfur content which makes it machinable poses another issue because of the associated lower alloying level which makes the alloy brittle, thus complicating the forming operations and wear of machining tools because of the accelerated wear of machining tools. Besides being lower in strength and brittle at the same time when compared to the other higher carbon steels, it may also get quite limited in its applications for high-stress conditions. Weldability gets adversely affected due to sulfur content, which necessitates the adoption of specialized techniques that do not result in weld defects. A good surface finish during the machining operation is usually achieved by employing the normalised 1215 steel but careful machining parameters and choice of tools becomes necessary if surface imperfections are observed. Overcoming these difficulties are vital in order to make the end product be of quality and perform well.

Common Applications of 1215 Carbon Steel


Motorcycle Parts:

Trailer Parts:

Bicycle Parts:

Go Kart Parts:

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