ThePipingMart Blog Grades AISI 12L14 Carbon Steel (UNS G12144) – Composition, Properties and Uses

AISI 12L14 Carbon Steel (UNS G12144) – Composition, Properties and Uses

SAE / AISI 12L14

AISI 12L14 is a low-carbon steel that offers superior workability and machinability. 12L14 Carbon Steel versatile alloy is used in a variety of industries and applications, such as automotive, manufacturing, and construction. Thanks to its low carbon content, 12L14 is easy to weld and can be used in a variety of welding applications. AISI 12L14 Carbon Steel, also known as UNS G12144, is a widely used material due to its unique composition and properties. The steel contains a high amount of lead, making it easy to machine and allowing for excellent machinability ratings. The lead also improves the surface finish and is beneficial for parts that require no additional treatment. AISI 12L14 Steel has a high sulfur content, which improves its chip-breaking capabilities and reduces tool wear. In addition, this steel has a moderately low tensile strength and is not suitable for high-stress applications. Overall, the unique composition and properties of AISI 12L14 Carbon Steel make it an excellent choice for many machining applications. Here’s a closer look at UNS G12144 versatile alloy and why it’s so popular among manufacturers.

What Forms of AISI 12L14 is Available at Piping Mart?

  • Nut
  • Bar
  • Bolt
  • Pipe
  • Screw
  • Tubing
  • Valves
  • Washers
  • Flanges
  • Fasteners
  • Electrodes
  • Stud Bolts
  • Sheet Plates
  • Pipe Fittings
  • Forged Fitting
  • Instrumentation Fittings

AISI 12L14 Composition

Element Content (%)
Iron, Fe 97.91 – 98.7
Manganese, Mn 0.85 – 1.15
Sulfur, S 0.260 – 0.35
Lead, Pb 0.15 – 0.35
Carbon, C  0.15
Phosphorous, P 0.040 – 0.090

AISI 12L14 Physical Properties

Properties Metric Imperial
Density 7.87 g/cm3 0.284 lb/in³

AISI 12L14 Mechanical Properties

Properties Metric Imperial
Tensile strength 540 MPa 78300 psi
Yield strength 415 MPa 60200 psi
Bulk modulus (typical for steel) 140 GPa 20300 ksi
Shear modulus (typical for steel) 80.0 GPa 11600 ksi
Elastic modulus 190-210 GPa 27557-30458 ksi
Poisson’s ratio 0.27-0.30 0.27-0.30
Elongation at break 10% 10%
Reduction of area 35% 35%
Hardness, Brinell 163 163
Hardness, Knoop (converted from Brinell hardness) 184 184
Hardness, Rockwell B (converted from Brinell hardness) 84 84
Hardness, Vickers (converted from Brinell hardness) 170 170
Machinability (based on 100 machinability for AISI 1212 steel) 160 160

AISI 12L14 Thermal Properties

Properties Metric Imperial
Thermal expansion co-efficient (@ 20°C/68°F, typical steel) 11.5 µm/m°C 6.39 µin/in°F
Thermal conductivity (typical steel) 51.9 W/mK 360 BTU in/hr.ft².°F

AISI 12L14 Equivalent

  • ASTM A576 (12L14)
  • SAE J1397 (12L14)
  • SAE J403 (12L14)
  • SAE J412 (12L14)
  • ASTM A108
  • ASTM A29
  • SAE J414

AISI 12L14 Uses

AISI 12L14 Carbon Steel (UNS G12144) is known for its excellent machining capabilities due to its high sulphur and lead content. This makes it a popular choice in the manufacturing industry for parts that require precision machining, such as fasteners, bushings, and fittings. Its machinability also allows for faster production times, making it an economical option. However, due to its low strength and ductility, it is not recommended for high-stress applications. Overall, AISI 12L14 Carbon Steel is a versatile material with many uses in the manufacturing industry.

AISI 12L14 Uses in Industries

  • Automotive parts: 12L14 is often used in the automotive industry thanks to its excellent machinability. This steel is often used to make car parts such as brake pads, fuel injectors, and engine blocks.
  • Manufacturing: This steel is also commonly used in the manufacturing industry. It can be used to make everything from nails and screws to bearings and shafts.
  • Construction: 12L14 can also be found in a variety of construction applications. This steel is often used to make pipes, beams, columns, and other structural elements.

AISI 12L14 Corrosion Resistance

12L14 offers excellent corrosion resistance thanks to its low carbon content. This steel is often used in environments where corrosion resistance is important, such as in the food processing or medical industries.

AISI 12L14 Heat Resistance

12L14 also has good heat resistance properties. This steel can withstand temperatures up to 900 degrees Fahrenheit without losing its strength or becoming brittle.

AISI 12L14 Machinability

12L14 has excellent machinability properties, which means it can be easily cut, drilled, milled, or shaped into the desired shape. This steel is also easy to weld, making it a popular choice for many different applications.

AISI 12L14 Welding

SAE/AISI 12L14 welding is an excellent choice for parts requiring machinable steel that is also weldable. It offers the characteristics of both mild steel and desulphurized or leaded steels, making it the ideal choice for parts made from materials such as shafts, bushings, pins, and other automotive and transportation components. Its unique chemistry has low carbon content, which provides high machinability in addition to its relatively good strength-to-weight ratio. Its use in welding is favoured for many applications due to its low phosphorus content, exceptional weldability without preheating or post-weld heat treatment, and minimum distortion when heated. 12L14 welding can also be machined easily with manual or automatic equipment due to its softness compared to other steels. These benefits make SAE/AISI 12L14 welding an ideal option for those looking for a durable material with exceptional machining properties.

AISI 12L14 Heat Treatment

Heat-treating SAE / AISI 12L14 steel is best done using industry standards for preheat and stress relief regulations, as this steel requires slightly different parameters than other steels. Preheating must be done at 750°F – 800° F, and the austenitizing temperature should not exceed 1200° F. This steel is usually annealed in a furnace; however, it can also be heated out-of-furnace with salt baths or similar heating methods. Quench it in oil or quench it and temper it to achieve the desired hardness range of 86-95 HRC. After heat treating, SAE / AISI 12L14 steel, the benefits include increased machinability and improved wear resistance due to increased hardness.


12L14 is a versatile alloy that offers superior machinability and weldability. Thanks to its low carbon content, this steel is also resistant to corrosion and has good heat resistance properties. If you’re looking for an alloy that can be easily shaped into the desired shape and that can withstand high temperatures without losing its strength, then 12L14 may be the perfect choice for your next project.

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