ThePipingMart Blog Grades AISI 4028 Alloy Steel (UNS G40280) – Composition, Properties and Uses

AISI 4028 Alloy Steel (UNS G40280) – Composition, Properties and Uses

AISI 4028 Steel

AISI 4028, a high-carbon steel alloy, boasts a carbon content ranging from 0.25% to 0.30%, positioning it as a frequently employed steel grade in the United States. This alloy exhibits corrosion and heat resistance, alongside easy machinability, rendering it versatile for various applications. Its favorable properties make AISI 4028 a preferred choice, balancing durability and workability in diverse industrial settings. When it comes to finding a steel alloy that provides a combination of strength, durability, and wear resistance, AISI 4028 Alloy Steel (UNS G40280) is a top contender. This alloy is crafted from a strong combination of elements, carbon, manganese, silicon, and chromium. Their collaborative interaction results in the creation of a high-strength steel exhibiting outstanding hardenability. Known by its industry designation of SAE-AISI 4028 steel, this alloy is a popular choice for various industries that require a reliable, long-lasting material that can handle tough conditions. Overall, AISI 4028 Alloy Steel (UNS G40280) is a top-choice for those looking for a strong, durable, and wear-resistant material. Let’s take a closer look at AISI 4028 versatile grade of steel.

What Forms of AISI 4028 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 4028 Chemical Composition

AISI 4028 chemical composition includes 0.25-0.30% carbon, contributing to hardness, 0.70-0.90% manganese for strength, 0.15-0.35% silicon aiding deoxidization, and 13% chromium enhancing hardenability. This combination forms a high-quality alloy with balanced properties, making AISI 4028 suitable for diverse applications where a blend of strength, durability, and machinability is crucial in industrial settings.

Element Content (%)
Iron, Fe 98.07 – 98.67
Manganese, Mn 0.70 – 0.90
Carbon, C 0.25 – 0.30
Molybdenum, Mo 0.20 – 0.30
Silicon, Si 0.15 – 0.35
Sulfur, S 0.035 – 0.050
Phosphorous, P 0.035

AISI 4028 Physical Properties

The density of AISI 4028, a high-carbon steel alloy, is approximately 7.85 grams per cubic centimeter (g/cm³). This density value reflects the mass per unit volume of the material and contributes to the overall characterization of AISI 4028. The moderate density and its specific composition make it suitable for applications where a balance between strength and weight is essential.
Properties Metric Imperial
Density 7.85 g/cm3 0.284 lb/in³

AISI 4028 Mechanical Properties

AISI 4028 exhibits mechanical properties such as a bulk modulus of approximately 140 GPa, elastic modulus around 190 GPa, and Poisson’s ratio of about 0.29. Its hardness values include Brinell hardness of 167-212, Rockwell B hardness of 91, and Vickers hardness of 199. These characteristics highlight its strength, resilience, and suitability for diverse applications.

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 167 – 212 167 – 212
Hardness, Knoop (converted from Brinell hardness) 212 212
Hardness, Rockwell B (converted from Brinell hardness) 91 91
Hardness, Rockwell C (converted from Brinell hardness. Value below normal HRC range, for comparison purposes only) 11 11
Hardness, Vickers (converted from Brinell hardness) 199 199
Machinability (annealed and cold drawn. Based on 100 machinability for AISI 1212 steel) 75 75

AISI 4028 Thermal Properties

Properties Metric Imperial
Thermal conductivity (typical steel) 44.5 W/mK 309 BTU in/hr.ft.°F

AISI 4028 Equivalent

  • ASTM A322
  • ASTM A331
  • ASTM A519
  • SAE J404
  • SAE J412
  • SAE J770

AISI 4028 Uses

The 4028-alloy steel stands out as a favored option across diverse applications, prized for its robustness, endurance, and adaptability. Commonly employed in automotive realms for crafting axle shafts, crankshafts, gears, and assorted components, it also finds extensive utility in aerospace and military domains where strength and heat resistance are paramount. Furthermore, its high wear resistance deems it fit for industrial tools, while its corrosion-resistant attributes make it a suitable choice for agricultural equipment.

AISI 4028 Uses in Industries

  • Automotive Industry
  • Construction Industry
  • Aerospace Industry
  • Oil and Gas Industry
  • Manufacturing Industry

AISI 4028 Corrosion Resistance

AISI 4028 has good corrosion resistance when compared with other steels in the same class. It resists oxidation at temperatures up to 815°F (435°C). The alloy also exhibits excellent uniformity of structure when exposed to corrosive environments over time. This makes it ideal for applications operating in harsh conditions or exposed to salt water or other corrosive agents.

AISI 4028 Heat Resistance

AISI 4028 has good heat resistance in comparison with other grades of steel in the same class. The elevated carbon content of this alloy serves as a shield, safeguarding against oxidation at high temperatures, reaching up to 815°F (435°C). The alloy also maintains good hardness levels when heated above 600°F (316°C), which makes it suitable for use in hot forging operations or high-temperature service applications such as furnace parts or turbine blades.

AISI 4028 Heat Treatment

To achieve maximum mechanical properties from AISI 4028 steel, it needs to be heat treated before being put into service. The alloy should be heated slowly until it reaches 1550–1600°F (843–871°C), then held at that temperature before being cooled at a rate no faster than 50°F (10°C) per hour until the desired hardness level is achieved. After cooling, the part should immediately be tempered or quenched depending on the desired mechanical properties needed from the final product.

AISI 4028 Machining

Due to its relatively low carbon content, AISI 4028 can be machined easily using conventional techniques such as turning and milling without any difficulty or special considerations needed during operation setup, like tool selection or cutting parameters adjustment. As an added bonus, the alloy does not require any post-machining treatments, such as stress relieving after the machining processes are complete.


In conclusion, AISI 4028 is an excellent material for many applications due to its versatility, durability, and strength. With proper heat treatment, it offers good corrosion resistance and machinability while being able to resist oxidation at temperatures up to 815° F (435 ° C). All these qualities make it an ideal choice for industries ranging from automotive manufacturing all the way through aerospace engineering so if you’re looking for a durable grade of steel with excellent thermal properties, consider giving AISI 4028 a try!

Related Post