ASTM A322
Basic Info
ASTM A322 outlines the requirements for alloy steel bars, specifying their chemical composition, mechanical properties, and heat treatment processes. This standard is significant for industries that utilize alloy steel bars in machinery components, gears, and structural applications, ensuring their strength and durability.
Description
Alloy Composition: A322 steel bars are alloyed for enhanced mechanical properties, such as increased strength and hardness.
Heat Treatment: The standard outlines heat treatment processes to achieve desired properties, such as through quenching and tempering.
Impact Resistance: A322 steel bars often have good impact resistance, suitable for parts in heavy machinery.
Uniformity: A322 specifies tight control over composition and processing, ensuring uniformity in properties.
ASTM A322 Data Sheet
Steel Grade
Dimensions and Tolerances
Equivalent Steel Grades
Chemical Composition
Mechanical Properties
Fabrication and Welding
Steel Grade
4130
4140
4340
6150
Dimensions and Tolerances
Steel Grade: 4130
- Round Bars:
Width: 6.35 – 101.6 mm
Tolerances: Diameter: ± 0.008 inch (± 0.20 mm)
- Hexagonal Bars:
Width: 6.35 – 76.2 mm
Tolerances: Across Flats: ± 0.007 inch (± 0.18 mm)
- Square Bars:
Width: 6.35 – 76.2 mm
Tolerances: Side: ± 0.005 inch (± 0.13 mm)
- Flat Bars:
Width: 12.7 – 152.4 mm
Thickness: 3.175 – 19.05 mm
Tolerances: Width: ± 0.005 inch (± 0.13 mm), Thickness: ± 0.005 inch (± 0.13 mm)
- Wide Flats:
Width: 12.7 – 152.4 mm
Thickness: 19.05 – 63.5 mm
Tolerances: Width: ± 0.005 inch (± 0.13 mm), Thickness: ± 0.005 inch (± 0.13 mm)
Steel Grade: 4140
- Round Bars:
Width: 6.35 – 101.6 mm
Tolerances: Diameter: ± 0.008 inch (± 0.20 mm)
- Hexagonal Bars:
Width: 6.35 – 76.2 mm
Tolerances: Across Flats: ± 0.007 inch (± 0.18 mm)
- Square Bars:
Width: 6.35 – 76.2 mm
Tolerances: Side: ± 0.005 inch (± 0.13 mm)
- Flat Bars:
Width: 12.7 – 152.4 mm
Thickness: 3.175 – 19.05 mm
Tolerances: Width: ± 0.005 inch (± 0.13 mm), Thickness: ± 0.005 inch (± 0.13 mm)
- Wide Flats:
Width: 12.7 – 152.4 mm
Thickness: 19.05 – 63.5 mm
Tolerances: Width: ± 0.005 inch (± 0.13 mm), Thickness: ± 0.005 inch (± 0.13 mm)
Steel Grade: 4340
- Round Bars:
Width: 6.35 – 101.6 mm
Tolerances: Diameter: ± 0.008 inch (± 0.20 mm)
- Hexagonal Bars:
Width: 6.35 – 76.2 mm
Tolerances: Across Flats: ± 0.007 inch (± 0.18 mm)
- Square Bars:
Width: 6.35 – 76.2 mm
Tolerances: Side: ± 0.005 inch (± 0.13 mm)
- Flat Bars:
Width: 12.7 – 152.4 mm
Thickness: 3.175 – 19.05 mm
Tolerances: Width: ± 0.005 inch (± 0.13 mm), Thickness: ± 0.005 inch (± 0.13 mm)
- Wide Flats:
Width: 12.7 – 152.4 mm
Thickness: 19.05 – 63.5 mm
Tolerances: Width: ± 0.005 inch (± 0.13 mm), Thickness: ± 0.005 inch (± 0.13 mm)
Steel Grade: 6150
- Round Bars:
Width: 6.35 – 101.6 mm
Tolerances: Diameter: ± 0.008 inch (± 0.20 mm)
- Hexagonal Bars:
Width: 6.35 – 76.2 mm
Tolerances: Across Flats: ± 0.007 inch (± 0.18 mm)
- Square Bars:
Width: 6.35 – 76.2 mm
Tolerances: Side: ± 0.005 inch (± 0.13 mm)
- Flat Bars:
Width: 12.7 – 152.4 mm
Thickness: 3.175 – 19.05 mm
Tolerances: Width: ± 0.005 inch (± 0.13 mm), Thickness: ± 0.005 inch (± 0.13 mm)
- Wide Flats:
Width: 12.7 – 152.4 mm
Thickness: 19.05 – 63.5 mm
Tolerances: Width: ± 0.005 inch (± 0.13 mm), Thickness: ± 0.005 inch (± 0.13 mm)
Equivalent Steel Grades
4130
- United Kingdom (BS 970): 708M40 / 709M40
- Germany (DIN): 25CrMo4 / 1.7218
- Japan (JIS): SCM430
4140
- United Kingdom (BS 970): 708M40 / 709M40
- Germany (DIN): 42CrMo4 / 1.7225
- Japan (JIS): SCM440
4340
- United Kingdom (BS 970): 817M40 / 826M40
- Germany (DIN): 34CrNiMo6 / 1.6582
- Japan (JIS): SNCM439
6150
- United Kingdom (BS 970): 735A51
- Germany (DIN): 50CrV4 / 1.8159
- Japan (JIS): SUP10
Chemical Composition
4130
- Carbon (C): 0.28–0.33
- Manganese (Mn): 0.40–0.60
- Phosphorus (P): 0.025 (max)
- Sulfur (S): 0.025 (max)
- Silicon (Si): 0.15–0.35
- Chromium (Cr): 0.80–1.10
- Molybdenum (Mo): 0.15–0.25
- Nickel (Ni): –
- Vanadium (V): –
4140
- Carbon (C): 0.38–0.43
- Manganese (Mn): 0.75–1.00
- Phosphorus (P): 0.025 (max)
- Sulfur (S): 0.025 (max)
- Silicon (Si): 0.15–0.35
- Chromium (Cr): 0.80–1.10
- Molybdenum (Mo): 0.15–0.25
- Nickel (Ni): –
- Vanadium (V): –
4340
- Carbon (C): 0.38–0.43
- Manganese (Mn): 0.60–0.80
- Phosphorus (P): 0.025 (max)
- Sulfur (S): 0.025 (max)
- Silicon (Si): 0.15–0.35
- Chromium (Cr): 0.80–1.10
- Molybdenum (Mo): 0.20–0.30
- Nickel (Ni): 1.65–2.00
- Vanadium (V): –
6150
- Carbon (C): 0.48–0.53
- Manganese (Mn): 0.70–0.90
- Phosphorus (P): 0.025 (max)
- Sulfur (S): 0.025 (max)
- Silicon (Si): 0.15–0.35
- Chromium (Cr): 0.80–1.10
- Molybdenum (Mo): –
- Nickel (Ni): –
- Vanadium (V): 0.15–0.30
Mechanical Properties
4130
- Tensile Strength (MPa): 689–931
- Yield Strength (MPa): 517–724
- Elongation (%): 20 (min)
- Reduction in Area (%): 45 (min)
- Hardness (HRC): 18–22
4140
- Tensile Strength (MPa): 655–815
- Yield Strength (MPa): 415–655
- Elongation (%): 20 (min)
- Reduction in Area (%): 45 (min)
- Hardness (HRC): 20–24
4340
- Tensile Strength (MPa): 745–1035
- Yield Strength (MPa): 470–815
- Elongation (%): 15 (min)
- Reduction in Area (%): 40 (min)
- Hardness (HRC): 24–32
6150
- Tensile Strength (MPa): 760–965
- Yield Strength (MPa): 620–655
- Elongation (%): 13 (min)
- Reduction in Area (%): 36 (min)
- Hardness (HRC): 38–43
Fabrication and Welding
4130
- Can be welded using all conventional methods, but preheating and post-weld stress relief are recommended for thick sections.
- Suitable for fusion welding by all processes.
- Forging is recommended to be carried out between 1750–2050°F (954–1123°C), followed by slow cooling in the furnace or air.
- Annealing after forging is recommended at 1600°F (870°C), followed by slow furnace cooling at a rate of 25°F (14°C) per hour.
4140
- Preheating is recommended before welding, especially for thicker sections or intricate designs.
- Suitable for fusion welding by all processes.
- Post-weld heat treatment is usually required to restore mechanical properties and relieve residual stresses.
- Forging is typically done at 2150–2250°F (1177–1232°C), followed by slow cooling in the furnace or air.
4340
- Preheating is recommended before welding, especially for thicker sections or complex shapes.
- Suitable for fusion welding by all processes.
- Post-weld heat treatment is often necessary to prevent cracking and restore properties.
- Forging is typically done at 2200–1600°F (1204–871°C), followed by air cooling or furnace cooling.
6150
- Preheating is recommended before welding, especially for thicker sections.
- Suitable for fusion welding by all processes.
- Post-weld heat treatment is usually required to restore mechanical properties and relieve residual stresses.
- Forging is typically done at 2200–1600°F (1204–871°C), followed by air cooling or furnace cooling.
Forged in Strength: Unveiling the Power of ASTM A322 Steel Grades
In the realm of industrial prowess, the pursuit of materials with unparalleled strength and resilience reigns supreme. Enter ASTM A322 steel, a formidable array of grades including 4130, 4140, 4340, and 6150, each a testament to the metallurgical artistry of modern engineering. Among the myriad of features that entice customers, it is the exceptional mechanical properties of these steels that truly captivate.
ASTM A322 steel grades are not merely components; they are the building blocks of innovation and reliability. With tensile strengths ranging from 655 MPa to an impressive 1035 MPa, and yield strengths from 415 MPa to 855 MPa, these steels are the epitome of structural integrity. Yet, their allure extends beyond raw power; boasting elongation percentages of up to 20%, they offer the promise of durability without compromise.
Picture components forged to perfection, whether it’s the impact resistance of 4340 or the spring-like qualities of 6150. ASTM A322 steel grades open doors to a realm of possibilities for engineers and manufacturers alike. From aerospace marvels to automotive essentials, these steels are the bedrock of reliability and performance. When strength is the foundation of success, ASTM A322 stands tall as the cornerstone of ingenuity and endurance.
