SAE/AISI 1340 Carbon Steel (UNS G13400)
SAE/AISI 1340 carbon steel is a medium-carbon, resulfurized alloy valued for its strength, toughness, and machinability. It performs well under high loads and is ideal for forged components like axles, gears, and crankshafts in heavy-duty applications, making it a popular choice across automotive and industrial sectors.
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| Chemical Composition | ||
|---|---|---|
| Element | Min | Max |
| Iron | 97.25% | 97.87% |
| Carbon | 0.38% | 0.43% |
| Manganese | 1.60% | 1.90% |
| Phosphorous | —— | 0.035% |
| Silicon | 0.15% | 0.35% |
| Sulfur | —— | 0.04% |
The following table provides a list of SAE/AISI 1340 properties in both SI and US customary/Imperial units.
Click on the button to switch between Metric and Imperial units.
| Physical Properties | Metric |
|---|---|
| Density | 7870 kg/m3 |
| Mechanical Properties | Metric |
| Tensile Strength (Ultimate) | 703 MPa |
| Tensile Strength (Yield) | 434 MPa |
| Young’s Modulus (E) | 190 - 210 GPa |
| Bulk Modulus (K) | 140 GPa |
| Shear Modulus (G) | 80 GPa |
| Elongation at Break | 26% |
| Reduction of Area | 57% |
| Poisson’s Ratio (ν) | 0.27 - 0.30 |
| Brinell Hardness | 207 |
| Thermal Properties | Metric |
| Thermal Conductivity | 52 W/m·K |
| Specific Heat Capacity (Cp) | 470 J/kg·K |
| Coefficient of Thermal Expansion (αL) | 1.15×10-5 1/°C |
| Electrical Properties | Metric |
| Electrical Conductivity | 4.18×106 S/m |
| Electrical Resistivity | 2.4×10-7 Ω·m |
The values in this table are approximate and can vary depending on various factors such as the specific manufacturing process and heat treatment applied to the alloy.
Advantages & Disadvantages of 1340 Carbon Steel
| Advantages | Disadvantages |
|---|---|
| High strength and toughness | Limited corrosion resistance |
| Good wear resistance | Susceptible to cracking under high stress |
| Suitable for heavy-duty applications | Requires proper heat treatment for optimal properties |
| Versatile and widely available | Relatively higher carbon content may lead to lower weldability |
| Cost-effective option | Not as impact-resistant as some other alloys |
| Can be easily machined and fabricated | Requires careful handling to prevent deformation during heat treatment |
Applications of 1340 Carbon Steel
Due to its excellent mechanical strength, wear resistance, and forgeability, SAE/AISI 1340 carbon steel is widely used across various industrial sectors, including:
- Axles and Shafts: Often used for manufacturing axles and shafts in automotive, heavy machinery, and transportation industries. Its high strength and toughness make it suitable for handling heavy loads and resisting wear.
- Gears and Gear Components: The excellent wear resistance makes it well-suited for gears and gear components. It can withstand the high stresses and abrasive forces associated with power transmission and motion control systems.
- Crankshafts: Crankshafts in engines require high strength and durability. Its mechanical properties make it an appropriate choice for manufacturing crankshafts that can withstand the alternating stresses and rotational forces.
- Forged Components: The forgeability makes it suitable for producing various forged components such as connecting rods, flanges, and other heavy-duty industrial parts. Its strength and toughness allow for reliable performance in demanding applications.
- Tooling and Machine Components: Due to its versatility and machinability, it is used for producing tooling components such as dies, punches, and cutting tools. It provides the necessary hardness and wear resistance required for these applications.
- Structural Components: In certain cases, it may be used in the construction of structural components, especially in applications where moderate strength and toughness are required.