4140 is a Chromium-Molybdenum through-hardening steel of medium hardenability. It is a general purpose high-tensile steel with medium strength level and good impact properties
Related Specifications
Grade AS1444 Grade 4140
ASTM A434 (A29) Grade 414
Euronorm EN 10083 grade 42CrMo4 (Material Number 1.7225/17227).
Chemical Composition
C Si Mn P S Cr Mo
0.37-0.44 0.10-0.35 0.65-1.10 ≤ 0.040 ≤ 0.040 0.75-1.20 0.15-0.30
Mechanical Properties
4140 is supplied in the hardened and tempered condition. The level of hardness is selected to give useful strength while still maintaining the ability to machine the material into finished components.
4140 can be re-heat-treated to higher strength or tempered back to lower strength levels than those supplied as standard. Assistance with heat treatment should be sought from reputable heat treatment companies.
Product: Atlas4140.pdf
More information:
ASTM A434 (A29) Grade 4140 steel is a low-alloy steel that
contains chromium, molybdenum, and manganese. It is commonly referred to as
"Chromoly" steel, which is a combination of the words
"chromium" and "molybdenum". This type of steel is known
for its high tensile strength, toughness, and abrasion resistance, making it
ideal for use in various industrial applications.
Grade 4140 steel is typically used in applications where high
strength and toughness are required, such as in the manufacture of tools,
gears, axles, shafts, and other machine parts. It is also commonly used in the
automotive and aerospace industries, as well as in the oil and gas industry.
ASTM A434 (A29) is the standard specification for hot-wrought
alloy steel bars that are used for general applications. Grade 4140 is included
in this specification, which sets the standards for chemical composition,
mechanical properties, and heat treatment of the steel.
The chemical composition of Grade 4140 steel typically
includes around 0.38-0.43% carbon, 0.75-1.00% manganese, 0.15-0.35% silicon,
0.80-1.10% chromium, 0.15-0.25% molybdenum, and small amounts of other elements
such as phosphorus and sulfur. The steel can be heat treated to achieve a wide
range of mechanical properties, including high tensile strength, yield
strength, and hardness.
Overall, ASTM A434 (A29) Grade 4140 steel is a popular and
versatile low-alloy steel that is widely used in various industrial
applications due to its excellent mechanical properties, durability, and
abrasion resistance.
Equivalent grades in other standards:
ASTM A434 (A29) Grade 4140 steel has equivalent grades in other standards, including:
- SAE 4140 steel (SAE J404)
- EN 1.7225 steel (EN 10083-3)
- DIN 42CrMo4 steel (DIN 17200)
SAE 4140 steel is the most commonly used alternative to ASTM A434 (A29) Grade 4140 steel in North America, and it has similar chemical composition and mechanical properties.
EN 1.7225 steel and DIN 42CrMo4 steel are European equivalents to ASTM A434 (A29) Grade 4140 steel, and they are widely used in Europe and other parts of the world. These grades have similar chemical composition and mechanical properties to ASTM A434 (A29) Grade 4140 steel, but there may be some minor differences in specific tolerances and testing methods.
Other equivalent standards to ASTM A434 (A29) Grade 4140 steel include BS 970-1955 EN19, ISO 683-1 Grade 4140, JIS G4105 Grade SCM440, and GB/T 3077 Grade 42CrMo.
It is important to note that while these standards are generally interchangeable, there may be some minor differences in chemical composition, mechanical properties, and testing requirements. Therefore, it is important to check the specific requirements of each standard before selecting a material for a particular application.
Chemical Composition
The chemical composition of ASTM A434 (A29) Grade 4140 steel
typically includes the following elements:
- Carbon
(C): 0.38% - 0.43%
- Manganese
(Mn): 0.75% - 1.00%
- Phosphorus
(P): 0.035% (max)
- Sulfur
(S): 0.040% (max)
- Silicon
(Si): 0.15% - 0.35%
- Chromium
(Cr): 0.80% - 1.10%
- Molybdenum
(Mo): 0.15% - 0.25%
The exact composition may vary depending on the manufacturing process and the specific grade of the material.
Mechanical properties:
Grade 4140 steel is a low-alloy steel that exhibits
excellent mechanical properties, including high tensile strength, good
ductility, and high toughness. The typical mechanical properties of Grade 4140
steel are:
- Tensile
strength: 655 MPa (95,000 psi)
- Yield
strength: 415 MPa (60,000 psi)
- Elongation
at break: 25%
- Reduction
of area: 50%
Physical properties:
Grade 4140 steel has a density of 7.85 g/cm3 (0.284 lb/in3),
a melting point of 1416 °C (2580 °F), and a specific heat capacity of 0.49
J/g·°C.
Thermal properties:
Grade 4140 steel has a thermal conductivity of 42.7 W/m·K
(296 BTU/h·ft·°F), a coefficient of thermal expansion of 12.3 µm/m·°C (6.83
µin/in·°F), and a specific heat capacity of 0.49 J/g·°C.
Corrosion resistance:
Grade 4140 steel has good corrosion resistance due to the
presence of chromium and molybdenum in its composition. However, it is not as
corrosion resistant as stainless steels and may require additional protective
coatings in certain applications.
Application
ASTM A434 (A29) Grade 4140 steel
is widely used in various industrial applications due to its excellent
mechanical properties, durability, and abrasion resistance. Some common
applications for this type of steel include:
- Machine components: Grade 4140 steel is commonly used
to manufacture machine components such as gears, axles, and shafts, due to
its high tensile strength and toughness.
- Tooling: The toughness and wear resistance of this
steel make it ideal for use in tooling applications such as molds, dies,
and cutting tools.
- Automotive industry: Grade 4140 steel is used in
various automotive components such as crankshafts, axle shafts, and
steering components, due to its high strength and durability.
- Aerospace industry: The high strength and toughness
of Grade 4140 steel make it suitable for use in various aerospace
applications, such as landing gear components, engine parts, and
structural components.
- Oil and gas industry: This steel is commonly used in
the oil and gas industry for applications such as drill collars, drill
pipes, and valve components, due to its high strength and corrosion
resistance.
- Construction industry: Grade 4140 steel is also used in construction applications such as bridge components, heavy machinery, and mining equipment.
