ThePipingMart Blog Grades SAE/AISI 4615 Alloy Steel (UNS G43350) – Composition, Properties and Uses

SAE/AISI 4615 Alloy Steel (UNS G43350) – Composition, Properties and Uses

SAE / AISI 4615 Steel

SAE / AISI 4615 is a medium-carbon steel alloy with good strength, toughness, and ductility. It is comprised of 0.45-0.50% carbon, 0.60-0.90% manganese, 0.04% sulfur, and 0.04% phosphorus. The combination of these elements makes it ideal for applications that require strong, heat-treated steel with excellent machinability and corrosion resistance. AISI 4615 Alloy Steel (UNS G43350) is a type of alloy steel known for its excellent balance of strength, toughness, and hardenability. With a composition that includes chromium, manganese, and molybdenum, this steel has high corrosion resistance and can withstand extreme temperatures. The properties of AISI 4615 Alloy Steel make it an ideal choice for various applications in the automotive, aerospace, and manufacturing industries. Whether you are looking for a material that can withstand high levels of stress or one that can be easily machined, AISI 4615 Alloy Steel is a solid choice. So, if you’re looking for a durable and versatile alloy steel, UNS G43350 might be the material you need. In this blog post, we’ll explore the uses of SAE/AISI 4615, its corrosion resistance and heat resistance capabilities, as well as its heat treatment and machining abilities.

What Forms of AISI 4615 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 4615 Composition

Element Content (%)
Iron, Fe 96.495 – 97.42
Nickel, Ni 1.65 – 2
Manganese, Mn 0.45 – 0.65
Molybdenum, Mo 0.20 – 0.30
Silicon, Si 0.15 – 0.30
Carbon, C 0.13 – 0.18
Sulfur, S ≤0.040
Phosphorous, P ≤0.035

AISI 4615 Physical Properties

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

AISI 4615 Mechanical Properties

Properties Metric Imperial
Modulus of elasticity 205 GPa 29700 ksi
Bulk modulus 140 GPa 20300 ksi
Shear modulus 80 GPa 11600 ksi
Poisson’s ratio 0.29 0.29
Hardness, Brinell 170 – 212 170 – 212
Hardness, Vickers 200 200
Hardness, Knoop 213 213
Hardness, Rockwell C 11 11
Hardness, Rockwell B 91 91
Machinability 65% 65%

AISI 4615 Thermal Properties

Properties Metric Imperial
Thermal expansion co-efficient (@20°C/68°F) 11 µm/m°C 6.11 µin/in°F
Thermal conductivity 44.5 W/mK 309².°F

AISI 4615 Equivalent

  • AMS 6290
  • AMS 6290C
  • ASTM A322
  • ASTM A331
  • ASTM A505
  • MIL SPEC MIL-S-7493
  • SAE J404
  • SAE J412
  • SAE J770

AISI 4615 Uses

SAE / AISI 4615 is used in various applications, including gears, shafts, axles, bolts and studs, and in construction materials like beams and plates. It can also be found in automotive components such as valve bodies and engine blocks due to its good strength at elevated temperatures up to 500 degrees F (260 degrees C). It has even been used for gun barrels due to its high hardness after heat treatment.

AISI 4615 Uses in Industries

Automotive Industry

One of the primary uses of AISI 4615 steel is in the automotive industry. This type of steel is commonly used to make gears, shafts, and other vehicle components. Its high strength and wear resistance make it ideal for transmission systems and other critical parts requiring durability and reliability.

Aerospace Industry

AISI 4615 steel is also widely used in the aerospace industry due to its high strength-to-weight ratio and excellent fatigue resistance. It is commonly used to make landing gear components, engine parts, and other critical aircraft structures that withstand extreme conditions.

Construction Industry

AISI 4615 steel is often used in the construction industry to make heavy-duty machinery and equipment such as cranes, bulldozers, and excavators. Its toughness and impact resistance make it suitable for handling heavy loads and withstanding harsh working environments.

Oil & Gas Industry

The oil and gas industry relies heavily on AISI 4615 steel for its drilling equipment, pipelines, and other infrastructure. This type of steel can withstand high pressure and corrosive environments, making it a crucial material for extracting and transporting oil and gas.

Manufacturing Industry

AISI 4615 steel is commonly used in various manufacturing processes due to its versatility and strength. It can be easily machined into different shapes and sizes while maintaining its mechanical properties, making it suitable for various applications in industries such as machinery production, toolmaking, and metalworking.

AISI 4615 Corrosion Resistance

The addition of manganese to the mix makes SAE/AISI 4615 highly resistant to corrosion in both acidic and alkaline environments without the need for surface treatments like plating or painting. This makes it an excellent choice for applications that will be exposed to harsh environmental conditions where surface treatments could be detrimental to performance or aesthetic appeal. Additionally, it is highly resistant to stress corrosion cracking when exposed to chloride ions which can cause problems with other types of steel over time.

AISI 4615 Heat Resistance

SAE/AISI 4615 has excellent heat resistance up to 500 degrees F (260 degrees C). This makes it an ideal choice for applications requiring strong steel that can handle extreme temperatures without losing structural integrity or becoming too brittle or soft over time. Additionally, this type of steel maintains its strength even after long periods of exposure to high temperatures making it suitable for continuous-duty application parts like valves or pumps, which may operate continuously at elevated temperatures over extended periods of time without fatigue failure from overheating or softening from prolonged exposure to high-temperature environments.

AISI 4615 Heat Treatment

SAE/AISI 4615 is typically hardened by quenching in oil, followed by tempering at relatively low temperatures (from 400–500°F). This process helps improve the properties such as ductility and toughness while also increasing the hardness so that the steel can better resist wear from friction or abrasion caused by contact with other metals or surfaces during use in applications like gears or bearings, which require high levels of wear resistance over long periods of time due to continuous contact between moving parts under load during operation.

AISI 4615 Machining

Machining this type of steel requires special care due to its higher carbon content which increases cutting forces on tooling compared to lower carbon steels but can still be done easily using appropriate tooling designed specifically for machining higher carbon steels such as carbide tipped tools instead of high-speed steel tools. Additionally, proper lubricants should always be used when machining this type of material since they help reduce friction during cutting operations while also helping protect the tools from excessive wear due to particulate buildup on cutting surfaces.

AISI 4615 Welding

Welding this type of steel requires special consideration because it tends to get brittle when heated up above 1000°F so welding should always be done using low amperage settings below 600amps; otherwise, cracking may occur in welded joints if they are over-exposed to excessive heat during welding operations. Additionally, preheating before welding is recommended since it helps reduce thermal shock, which can lead to burning through under high amperage settings.


Sae/aisi4615 is a medium-carbon steel alloy that provides good strength and toughness along with excellent corrosion and heat resistance properties, making it suitable for a variety of applications requiring good wear resistance and high strength at elevated temperatures, such as gears or valves operating continuously.

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