ThePipingMart Blog Grades SAE/AISI 5135 Alloy Steel (UNS G51350) – Composition, Properties and Uses

SAE/AISI 5135 Alloy Steel (UNS G51350) – Composition, Properties and Uses

SAE / AISI 5135 Steel

AISI 5135 steel is a high-carbon, low-alloy structural steel used in a variety of applications. 5135 Alloy Steel has excellent machinability and weldability properties and provides good corrosion and heat resistance. This article will provide an overview of the properties and uses of UNS G51350, as well as detail its corrosion resistance, heat resistance, heat treatment, machining, and welding characteristics.

AISI 5135 Composition

Element Content (%)
Iron, Fe 97.445 – 98.17
Chromium, Cr 0.750 – 1.00
Manganese, Mn 0.600 – 0.800
Carbon, C 0.330 – 0.380
Silicon, Si 0.150 – 0.300
Sulfur, S ≤ 0.0400
Phosphorous, P ≤ 0.0350

AISI 5135 Physical Properties

Properties Metric Imperial
Density 7.85 g/cm3 0.284 lb/in³

AISI 5135 Mechanical Properties

Properties Metric Imperial
Bulk modulus (typical for steel) 140 GPa 20300 ksi
Shear modulus (typical for steel) 80 GPa 11600 ksi
Elastic modulus 190-210 GPa 27557-30458 ksi
Poisson’s ratio 0.27-0.30 0.27-0.30
Hardness, Brinell (annealed and cold drawn) 179 – 217 179 – 217
Hardness, Knoop (converted from Brinell hardness) 220 220
Hardness, Rockwell B (converted from Brinell hardness) 92 92
Hardness, Rockwell C 13 13
Hardness, Vickers (converted from Brinell hardness) 208 208
Machinability (annealed and cold drawn. Based on 100 machinability for AISI 1212 steel) 70 70

AISI 5135 Thermal Properties

Properties Metric Imperial
Thermal conductivity (typical steel) 46.6 W/mK 323 BTU in/hr.ft².°F

AISI 5135 Equivalent

  • AFNOR 38 C 4
  • DIN 1.7034
  • UNI 38 Cr 4 KB
  • JIS SCr 3 H
  • B.S. 530 A 36
  • B.S. 530 H 36
  • B.S. Type 3
  • ASTM A322
  • ASTM A331
  • ASTM A519
  • SAE J404
  • SAE J412
  • SAE J770

AISI 5135 Uses

SAE/AISI 5135 steel is widely used in a variety of applications due to its wide range of mechanical properties. Its versatility makes it ideal for parts that require strength, wear resistance, toughness, and ductility. Common applications include gears and shafts for automotive components; hand tools; machine tools; agricultural equipment; screws; springs; fasteners; valves; pumps; studs; pins; nuts, and bolts.

Corrosion Resistance

SAE/AISI 5135 steel offers good corrosion resistance because it contains chromium (Cr) which helps form a protective oxide film on the surface. This film helps protect the metal from oxidation and corrosion caused by moisture or exposure to other corrosive elements such as acids or alkalis. The addition of nickel (Ni) also helps improve corrosion resistance by increasing the protective oxide film’s thickness.

Heat Resistance

SAE/AISI 5135 steel offers excellent heat resistance due to its high chromium (Cr) content which helps form a thick protective oxide film on the surface that prevents oxidation at elevated temperatures. Nickel (Ni) also helps improve heat resistance by helping increase the thickness of this protective film. In addition, the alloy’s low carbon content improves its ability to resist softening at higher temperatures.

Heat Treatment

Heat treatment can be used to alter the hardness and strength of SAE/AISI 5135 steel without significantly affecting its other mechanical properties, such as ductility and toughness. Commonly used heat treatments include quenching followed by tempering or normalizing followed by tempering or annealing followed by tempering, depending on the desired outcome. Quenching is used for higher hardness, normalizing is better for toughness, and annealing is best for enhanced ductility.


SAE/AISI 5135 steel offers excellent machinability due to its relatively low carbon content, which increases cutting speed while reducing power consumption during machining operations compared to higher carbon steels. Additionally, it has good wear resistance, which further improves machinability when dealing with difficult-to-machine materials such as stainless steel or aluminum alloys. It is recommended that slow speeds be used when turning, drilling, or milling this material to reduce tool wear while maximizing accuracy and precision in the finished product. Finally, using sharp cutting tools with positive rake angles will help produce smooth surfaces with minimal burrs during machining operations on this material type.


In conclusion, SAE/AISI 5135 steel is an excellent material choice for many engineering applications due to its versatile combination of strength, wear resistance, toughness, corrosion resistance, and heat resistance qualities, along with excellent machinability properties when combined with its weldability capabilities, make it suitable for most any job requiring these qualities such as gears, shafts automotive components hand tools machine tools agricultural equipment screws springs fasteners valves pumps studs pins nuts bolts etcetera. Furthermore, it can be easily heat treated in order to tailor fit its mechanical properties according to specific application needs making it an even more desirable material choice overall in many engineering projects worldwide today!

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SAE/AISI 5135 Alloy Steel (UNS G51350) – Composition, Properties and Uses

by Abhishek Modak time to read: 3 min