Heavy Plate
BMG’s specialized Heavy Plate division is dedicated to supplying manufacturers and builders with steel plates whose thickness reaches or exceeds three inches.
ASTM A829 / 4140 STEEL
ASTM A829 / 4140 is a high-strength chromium-molybdenum alloy steel widely used in industrial applications that require excellent wear resistance, toughness, and hardness. It is well known for its ability to withstand heavy loads, its good machinability, and its suitability for quench-and-temper heat treatment—making it an ideal choice for a broad range of mechanical and structural components.
ASTM A829 Grade 4140 is a chromium-molybdenum alloy steel that offers improved tensile strength, wear resistance, hardness, and toughness. It is commonly used to manufacture machinery parts, shafts, gears, and other structural and mechanical components that require high performance under severe conditions. 4140 steel can be heat treated to achieve different combinations of mechanical properties depending on specific application requirements.
- High wear resistance: ideal for components exposed to friction or heavy loading.
- Excellent tensile strength and hardness: well-suited for parts subjected to high mechanical stresses.
- Good toughness: strong resistance to fracture and deformation, including at elevated temperatures.
- Good machinability and heat-treat response: can be quenched and tempered to achieve the desired hardness and toughness.
Versatile: suitable for a wide range of applications, from machinery components to engineered structures.
- Automotive: axles, gears, camshafts, transmission components, and other critical vehicle parts.
- Heavy machinery: shafts, gears, and machine parts operating under high loads.
- Aerospace: aircraft parts including engine components and structural elements.
- Energy: parts for turbines, generators, and other critical components in power generation.
- Tools and molds: cutting tools and dies due to its strength and hardness.
Element | ASTM A829 / 4140 |
Carbon (C) | 0.38 – 0.43% |
Manganese (Mn) | 0.60 – 0.90% |
Phosphorus (P) | ≤ 0.035% |
Sulfur (S) | ≤ 0.035% |
Silicon (Si) | 0.20 – 0.35% |
Chromium (Cr) | 0.80 – 1.10% |
Molybdenum (Mo) | 0.15 – 0.25% |
Property | ASTM A829 / 4140 |
Tensile strength | 95 – 105 ksi [655 – 725 MPa] |
Yield strength (min.) | 70 ksi [485 MPa] |
Elongation in 8 in. [200 mm] (min.) | 18% |
Brinell hardness (max.) | 302 HBW |
Impact toughness (min.) | 40 ft-lb [54 J] at -40°F [-40°C] |
Thickness (mm) | Width (mm) | Length (mm) |
10 – 100 | 1000 – 2500 | 2500 – 12000 |
10 – 80 | 1000 – 3000 | 3000 – 12000 |
Can be supplied as bars or plates.
ASTM A829 / 4140 | Equivalent Grades |
ASTM A829 / 4140 | EN 10083-3 C40E |
ASTM A829 / 4140 | SAE 4140 |
ASTM A829 / 4140 | JIS SCM440 |
ASTM A829 / 4140 steel is an excellent choice for a wide range of industrial applications requiring high wear resistance, tensile strength, and toughness. Its ability to be quenched and tempered makes it a versatile material for critical machinery parts, vehicle components, and high-performance structural applications. With its robust chemical composition and mechanical properties, 4140 steel is a reliable solution for demanding service conditions.