SAE 1018 is a mild steel that’s used a lot in manufacturing and construction because it’s easy to work with and performs well. It has a low carbon content which gives it decent strength and makes it easier to machine weld and shape. That’s why it’s a popular choice for parts that don’t need to be extremely hard but still need to perform well and stay dependable Over the next sections we’ll break down what this material is made of how it behaves during processing how strong it is and where it’s most often used so you can decide if it’s the right match for your project.
What is SAE 1018?
SAE 1018 is a common low carbon steel listed under the AISI and SAE systems. It’s often called plain carbon steel because it has a simple composition. The number 1018 means it contains about 0.18 percent carbon which puts it in the low carbon range. That small amount of carbon makes it easy to weld and machine and if needed it can be heat treated on the surface to make it harder without changing the core.
SAE 1018 steel is widely produced in both cold-drawn and hot-rolled forms, each offering specific advantages. Cold-drawn 1018 is known for tighter tolerances, improved surface finish, and enhanced strength due to strain hardening, while hot-rolled 1018 is more cost-effective and easier to fabricate in bulk.
SAE 1018 Chemical Composition
The composition of SAE 1018 steel is relatively straightforward, which is part of its appeal. The elements present are carefully controlled to provide a consistent material response in different forming and processing conditions.
| Element | Percentage (%) |
| Carbon (C) | 0.14 – 0.20 |
| Manganese (Mn) | 0.60 – 0.90 |
| Phosphorus (P) | ≤ 0.040 |
| Sulfur (S) | ≤ 0.050 |
| Iron (Fe) | Remaining balance |
The low carbon and moderate manganese levels make SAE 1018 chemical composition suitable for parts that require good surface finish and dimensional accuracy after machining. These elements are present in ideal proportions to ensure the material remains machinable while still offering respectable strength.
SAE 1018 Mechanical Properties
The mechanical properties of SAE 1018 allow it to perform effectively under various mechanical stresses. It maintains structural integrity even when subjected to moderate loads and offers sufficient flexibility for bending and shaping.
| Property | Value |
| Tensile Strength | 440–540 MPa |
| Yield Strength | 370–420 MPa |
| Elongation at Break | 15%–23% |
| Reduction in Area | Around 40% |
| Brinell Hardness | 120–143 HB |
| Modulus of Elasticity | 205 GPa |
| Shear Modulus | 80 GPa |
| Poisson’s Ratio | 0.29 |
These SAE 1018 mechanical properties make this material ideal for parts such as axles, pins, and rods where some flexibility and wear resistance are needed.
Physical Properties of SAE 1018
| Property | Value |
| Density | 7.87 g/cm³ |
| Thermal Conductivity | 51.9 W/m·K at 0°C |
| Specific Heat | 486–599 J/kg·K |
| Coefficient of Expansion | 12–14.5 µm/m·°C |
| Electrical Resistivity | 0.16–0.29 μΩ·m |
The physical behavior of SAE 1018 further supports its reliability in industrial and mechanical systems.These properties help the steel keep its shape and size even when temperatures change which makes it a good choice for applications that involve heat or frequent thermal cycling.
Cold Drawn vs. Hot Rolled SAE 1018 Steel
Cold drawn SAE 1018 steel offers better strength and a smoother surface finish thanks to the work hardening process and more precise size control compared to hot rolled steel. It’s a good choice when you need precision like in shafts, bushings or pins. On the other hand hot rolled SAE 1018 is better for structural work where exact size and appearance don’t matter as much.
- Cold Drawn 1018 gives you more strength better machinability and tighter size control which makes it ideal when precision matters
- Hot Rolled 1018 is more affordable easier to work with and a good fit for general structural parts where looks and exact dimensions are not as important
The right choice depends on how much precision strength and appearance matter for your specific use
Heat Treatment and Surface Hardening of SAE 1018
SAE 1018 has low carbon content so it cannot be hardened all the way through but its surface can be made harder using case hardening methods. This gives it a tough outer layer while the inside stays strong and flexible. It works well for parts like gears and sprockets that need to resist wear but also handle stress without breaking.
| Treatment Method | Temperature Range | Cooling Method | Application |
| Annealing | 870–900°C | Furnace cooling | Stress relief and machinability |
| Carburizing | 900–925°C | Brine or oil quench | Surface hardening for gears, pins |
| Carbonitriding | 870°C | Oil quench + temper | Increases wear resistance |
Machinability and Fabrication of SAE 1018
SAE 1018 has a machinability rating of 70 percent which makes it a great choice for CNC machining and high speed production lines. It gives consistent chip control and allows for tight tolerances. Its balanced structure helps reduce tool wear and gives a smooth surface finish.
You can use SAE 1018 for stamping, drilling threading, turning, bending and forming. Since it handles cold working well and gives predictable results it is often used for precision parts and fixtures where accuracy really matters.
Welding Characteristics of SAE 1018
SAE 1018 Equivalent Material Grades
The global recognition of SAE 1018 is reinforced by its equivalents under different material standards.
| Standard | Equivalent Grade |
| ASTM | A108, A29, A512, A519 |
| DIN/EN | CK15, S235JR |
| JIS | S15C |
| GB (China) | 15 |
| ISO | ISO 630 |
| SAE | J403, J412, J414 |
These equivalent materials provide engineers with flexibility when sourcing steel globally while maintaining comparable quality.
SAE 1018 Steel Applications
The versatility of SAE 1018 steel allows it to serve in a wide range of engineering roles:
- Automotive Sector: Crankshafts, transmission gears, shafts, and axle studs
- Construction Equipment: Frame supports, joint plates, and connectors
- Industrial Machinery: Shafts, bushings, bearing races, pins, and brackets
- Consumer Manufacturing: Furniture frameworks, appliance supports, and fixtures
Many of these parts benefit from SAE 1018’s compatibility with carburizing and its ability to be shaped precisely without cracking.
SAE 1018 vs. Other Low-Carbon Steels
Compared to grades like SAE 1008 or SAE 1020, SAE 1018 offers a middle ground:
- SAE 1008: Lower carbon, superior ductility but lower strength
- SAE 1020: Slightly higher carbon, more strength but reduced machinability
- SAE 1018: Balanced machinability, strength, and forming performance
This makes SAE 1018 steel properties especially desirable for components that undergo multiple processes before assembly.
Industry Case Study Example of SAE 1018
Benefits of Using SAE 1018 Steel Material
- Easy to machine and fabricate
- Excellent weldability for structural assemblies
- Stable under heat and load cycles
- Good candidate for carburized or hardened surface finishes
- Compatible with multiple international standards
Limitations of SAE 1018 Steel
- Not suitable for very high-load or impact applications.
- Requires surface protection (e.g., painting, galvanizing) for corrosion resistance
- Cannot be heat treated through thickness like medium/high carbon steels
The Bottom Line
SAE 1018 steel remains an important material in both industrial and commercial use. It combines good strength, smooth finish and easy workability which makes it a reliable choice for manufacturers everywhere. Whether it is used in car parts or general fixtures SAE 1018 delivers the consistency and durability needed for efficient production and long service life.
Looking for a reliable SAE 1018 steel supplier?
At Kalpataru Piping Solutions we provide top quality SAE 1018 material that meets global standards for strength machining and fabrication. Whether you need hot rolled cold drawn or custom steel solutions our team is ready to help you get the right material on time and within your budget Contact us for bulk orders technical guidance or any special requirements based on your industry needs.
